Effect of temperature on the AC impedance of protein and ...

Indian Academy of Sciences (India)

2016-08-26

Aug 26, 2016 ... The depression parameter reveals the electrical equivalent circuit for the biopolymers. The AC electrical conductivity in the biopolymers follows the universal power law. From this, it is observed that the AC conductivity is frequency dependent and the biopolymer papain obeys large polaron tunnelling model ...

The sluggs survey: HST/ACS mosaic imaging of the NGC 3115 globular cluster system

Energy Technology Data Exchange (ETDEWEB)

Jennings, Zachary G.; Romanowsky, Aaron J.; Brodie, Jean P.; Arnold, Jacob A. [University of California Observatories, Santa Cruz, CA 95064 (United States); Strader, Jay [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, MI 48824 (United States); Lin, Dacheng; Irwin, Jimmy A.; Wong, Ka-Wah [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Sivakoff, Gregory R., E-mail: zgjennin@ucsc.edu [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

2014-08-01

We present Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) g and z photometry and half-light radii R {sub h} measurements of 360 globular cluster (GC) candidates around the nearby S0 galaxy NGC 3115. We also include Subaru/Suprime-Cam g, r, and i photometry of 421 additional candidates. The well-established color bimodality of the GC system is obvious in the HST/ACS photometry. We find evidence for a 'blue tilt' in the blue GC subpopulation, wherein the GCs in the blue subpopulation get redder as luminosity increases, indicative of a mass-metallicity relationship. We find a color gradient in both the red and blue subpopulations, with each group of clusters becoming bluer at larger distances from NGC 3115. The gradient is of similar strength in both subpopulations, but is monotonic and more significant for the blue clusters. On average, the blue clusters have ∼10% larger R {sub h} than the red clusters. This average difference is less than is typically observed for early-type galaxies but does match that measured in the literature for the Sombrero Galaxy (M104), suggesting that morphology and inclination may affect the measured size difference between the red and blue clusters. However, the scatter on the R {sub h} measurements is large. We also identify 31 clusters more extended than typical GCs, which we term ultra-compact dwarf (UCD) candidates. Many of these objects are actually considerably fainter than typical UCDs. While it is likely that a significant number will be background contaminants, six of these UCD candidates are spectroscopically confirmed as NGC 3115 members. To explore the prevalence of low-mass X-ray binaries in the GC system, we match our ACS and Suprime-Cam detections to corresponding Chandra X-ray sources. We identify 45 X-ray-GC matches: 16 among the blue subpopulation and 29 among the red subpopulation. These X-ray/GC coincidence fractions are larger than is typical for most GC systems, probably due to the increased

The Sloan Lens ACS Survey. XIII. Discovery of 40 New Galaxy-scale Strong Lenses

Science.gov (United States)

Shu, Yiping; Brownstein, Joel R.; Bolton, Adam S.; Koopmans, Léon V. E.; Treu, Tommaso; Montero-Dorta, Antonio D.; Auger, Matthew W.; Czoske, Oliver; Gavazzi, Raphaël; Marshall, Philip J.; Moustakas, Leonidas A.

2017-12-01

We present the full sample of 118 galaxy-scale strong-lens candidates in the Sloan Lens ACS (SLACS) Survey for the Masses (S4TM) Survey, which are spectroscopically selected from the final data release of the Sloan Digital Sky Survey. Follow-up Hubble Space Telescope (HST) imaging observations confirm that 40 candidates are definite strong lenses with multiple lensed images. The foreground-lens galaxies are found to be early-type galaxies (ETGs) at redshifts 0.06–0.44, and background sources are emission-line galaxies at redshifts 0.22–1.29. As an extension of the SLACS Survey, the S4TM Survey is the first attempt to preferentially search for strong-lens systems with relatively lower lens masses than those in the pre-existing strong-lens samples. By fitting HST data with a singular isothermal ellipsoid model, we find that the total projected mass within the Einstein radius of the S4TM strong-lens sample ranges from 3 × 1010 M ⊙ to 2 × 1011 M ⊙. In Shu et al., we have derived the total stellar mass of the S4TM lenses to be 5 × 1010 M ⊙ to 1 × 1012 M ⊙. Both the total enclosed mass and stellar mass of the S4TM lenses are on average almost a factor of 2 smaller than those of the SLACS lenses, which also represent the typical mass scales of the current strong-lens samples. The extended mass coverage provided by the S4TM sample can enable a direct test, with the aid of strong lensing, for transitions in scaling relations, kinematic properties, mass structure, and dark-matter content trends of ETGs at intermediate-mass scales as noted in previous studies. Based on observations made with the NASA/ESA Hubble Space Telescope (HST), obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. These observations are associated with HST program #12210.

Phase I Cultural Resources Survey and Archeological Inventory of a Proposed 1.12 ha (2.87 ac) Borrow Pit and an Associated Access Road, Ascension Parish, Louisiana

National Research Council Canada - National Science Library

Labadia, Catherine; Pokrant, Marie; Pincoske, Jeremy; George, David

2004-01-01

... (northeast of River Mile 180), and it measures approximately 1.16 ha (2.87 ac) in size. This area was subject to pedestrian survey and backhoe trenching in order to identify any subsurface cultural features or material...

AC Initiation System.

Science.gov (United States)

An ac initiation system is described which uses three ac transmission signals interlocked for safety by frequency, phase, and power discrimination...The ac initiation system is pre-armed by the application of two ac signals have the proper phases, and activates a load when an ac power signal of the proper frequency and power level is applied. (Author)

Interactive Poster Survey Study of ACS Members' Knowledge and Needs on Research Ethics

Science.gov (United States)

Mabrouk, Patricia Ann; Schelble, Susan M.

2018-01-01

An interactive poster exhibited at two poster sessions at the Fall 2016 American Chemical Society (ACS) National Meeting was used as a vehicle to learn about ACS members' concerns and needs related to research ethics and to identify opportunities for engagement of the Society by the Committee on Ethics (ETHX) and others in terms of ethics…

Context based computational analysis and characterization of ARS consensus sequences (ACS of Saccharomyces cerevisiae genome

Directory of Open Access Journals (Sweden)

Vinod Kumar Singh

2016-09-01

Full Text Available Genome-wide experimental studies in Saccharomyces cerevisiae reveal that autonomous replicating sequence (ARS requires an essential consensus sequence (ACS for replication activity. Computational studies identified thousands of ACS like patterns in the genome. However, only a few hundreds of these sites act as replicating sites and the rest are considered as dormant or evolving sites. In a bid to understand the sequence makeup of replication sites, a content and context-based analysis was performed on a set of replicating ACS sequences that binds to origin-recognition complex (ORC denoted as ORC-ACS and non-replicating ACS sequences (nrACS, that are not bound by ORC. In this study, DNA properties such as base composition, correlation, sequence dependent thermodynamic and DNA structural profiles, and their positions have been considered for characterizing ORC-ACS and nrACS. Analysis reveals that ORC-ACS depict marked differences in nucleotide composition and context features in its vicinity compared to nrACS. Interestingly, an A-rich motif was also discovered in ORC-ACS sequences within its nucleosome-free region. Profound changes in the conformational features, such as DNA helical twist, inclination angle and stacking energy between ORC-ACS and nrACS were observed. Distribution of ACS motifs in the non-coding segments points to the locations of ORC-ACS which are found far away from the adjacent gene start position compared to nrACS thereby enabling an accessible environment for ORC-proteins. Our attempt is novel in considering the contextual view of ACS and its flanking region along with nucleosome positioning in the S. cerevisiae genome and may be useful for any computational prediction scheme.

Autographa californica multiple nucleopolyhedrovirus ac53 plays a role in nucleocapsid assembly

International Nuclear Information System (INIS)

Liu Chao; Li Zhaofei; Wu Wenbi; Li Lingling; Yuan Meijin; Pan Lijing; Yang Kai; Pang Yi

2008-01-01

Autographa californica multiple nucleopolyhedrovirus (AcMNPV) orf53 (ac53) is a highly conserved gene existing in all sequenced Lepidoptera and Hymenoptera baculoviruses, but its function remains unknown. To investigate its role in the baculovirus life cycle, an ac53 deletion virus (vAc ac53KO-PH-GFP ) was generated through homologous recombination in Escherichia coli. Fluorescence and light microscopy and titration analysis revealed that vAc ac53KO-PH-GFP could not produce infectious budded virus in infected Sf9 cells. Real-time PCR demonstrated that the ac53 deletion did not affect the levels of viral DNA replication. Electron microscopy showed that many lucent tubular shells devoid of the nucleoprotein core are present in the virogenic stroma and ring zone, indicating that the ac53 knockout affected nucleocapsid assembly. With a recombinant virus expressing an Ac53-GFP fusion protein, we observed that Ac53 was distributed within the cytoplasm and nucleus at 24 h post-infection, but afterwards accumulated predominantly near the nucleus-cytoplasm boundary. These data demonstrate that ac53 is involved in nucleocapsid assembly and is an essential gene for virus production

Study on ac losses of HTS coil carrying ac transport current

International Nuclear Information System (INIS)

Dai Taozhen; Tang Yuejin; Li Jingdong; Zhou Yusheng; Cheng Shijie; Pan Yuan

2005-01-01

Ac loss has an important influence on the thermal performances of HTS coil. It is necessary to quantify ac loss to ascertain its impact on coil stability and for sizing the coil refrigeration system. In this paper, we analyzed in detail the ac loss components, hysteresis loss, eddy loss and flux flow loss in the pancake HTS coil carrying ac transport current by finite element method. We also investigated the distribution of the ac losses in the coil to study the effects of magnetic field distribution on ac losses

Multi-phase AC/AC step-down converter for distribution systems

Science.gov (United States)

Aeloiza, Eddy C.; Burgos, Rolando P.

2017-10-25

A step-down AC/AC converter for use in an electric distribution system includes at least one chopper circuit for each one of a plurality of phases of the AC power, each chopper circuit including a four-quadrant switch coupled in series between primary and secondary sides of the chopper circuit and a current-bidirectional two-quadrant switch coupled between the secondary side of the chopper circuit and a common node. Each current-bidirectional two-quadrant switch is oriented in the same direction, with respect to the secondary side of the corresponding chopper circuit and the common node. The converter further includes a control circuit configured to pulse-width-modulate control inputs of the switches, to convert a first multiphase AC voltage at the primary sides of the chopper circuits to a second multiphase AC voltage at the secondary sides of the chopper circuits, the second multiphase AC voltage being lower in voltage than the first multiphase AC voltage.

A Survey of Electronic Serials Managers Reveals Diversity in Practice

Directory of Open Access Journals (Sweden)

Laura Costello

2014-09-01

Full Text Available A Review of: Branscome, B. A. (2013. Management of electronic serials in academic libraries: The results of an online survey. Serials Review, 39(4, 216-226. http://dx.doi.org/10.1016/j.serrev.2013.10.004 Abstract Objective – To examine industry standards for the management of electronic serials and measure the adoption of electronic serials over print. Design – Survey questionnaire. Setting – Email lists aimed at academic librarians working in serials management. Subjects – 195 self-selected subscribers to serials email lists. Methods – The author created a 20 question survey that consisted primarily of closed-ended questions pertaining to the collection demographics, staff, budget, and tools of serials management groups in academic libraries. The survey was conducted via Survey Monkey and examined using the analytical features of the tool. Participants remained anonymous and the survey questions did not ask them to reveal identifiable information about their libraries. Main Results – Collection demographics questions revealed that 78% of surveyed librarians estimated that print-only collections represented 40% or fewer of their serials holdings. The author observed diversity in the factors that influence print to digital transitions in academic libraries. However 71.5% of participants indicated that publisher technology support like IP authentication was required before adopting digital subscriptions. A lack of standardization also marked serials workflows, department responsibilities, and department titles. The author did not find a correlation between serials budget and the enrollment size of the institution. Participants reported that they used tools from popular serials management vendors like Serials Solutions, Innovative Interfaces, EBSCO, and Ex Libris, but most indicated that they used more than one tool for serials management. Participants specified 52 unique serials management products used in their libraries. Conclusion �

Gamma-irradiation produces active chlorine species (ACS) in physiological solutions: Secoisolariciresinol diglucoside (SDG) scavenges ACS - A novel mechanism of DNA radioprotection.

Science.gov (United States)

Mishra, Om P; Popov, Anatoliy V; Pietrofesa, Ralph A; Christofidou-Solomidou, Melpo

2016-09-01

Secoisolariciresinol diglucoside (SDG), the main lignan in whole grain flaxseed, is a potent antioxidant and free radical scavenger with known radioprotective properties. However, the exact mechanism of SDG radioprotection is not well understood. The current study identified a novel mechanism of DNA radioprotection by SDG in physiological solutions by scavenging active chlorine species (ACS) and reducing chlorinated nucleobases. The ACS scavenging activity of SDG was determined using two highly specific fluoroprobes: hypochlorite-specific 3'-(p-aminophenyl) fluorescein (APF) and hydroxyl radical-sensitive 3'-(p-hydroxyphenyl) fluorescein (HPF). Dopamine, an SDG structural analog, was used for proton (1)H NMR studies to trap primary ACS radicals. Taurine N-chlorination was determined to demonstrate radiation-induced generation of hypochlorite, a secondary ACS. DNA protection was assessed by determining the extent of DNA fragmentation and plasmid DNA relaxation following exposure to ClO(-) and radiation. Purine base chlorination by ClO(-) and γ-radiation was determined by using 2-aminopurine (2-AP), a fluorescent analog of 6-aminopurine. Chloride anions (Cl(-)) consumed >90% of hydroxyl radicals in physiological solutions produced by γ-radiation resulting in ACS formation, which was detected by (1)H NMR. Importantly, SDG scavenged hypochlorite- and γ-radiation-induced ACS. In addition, SDG blunted ACS-induced fragmentation of calf thymus DNA and plasmid DNA relaxation. SDG treatment before or after ACS exposure decreased the ClO(-) or γ-radiation-induced chlorination of 2-AP. Exposure to γ-radiation resulted in increased taurine chlorination, indicative of ClO(-) generation. NMR studies revealed formation of primary ACS radicals (chlorine atoms (Cl) and dichloro radical anions (Cl2¯)), which were trapped by SDG and its structural analog dopamine. We demonstrate that γ-radiation induces the generation of ACS in physiological solutions. SDG treatment scavenged

AC – AC Converters for UPS

Directory of Open Access Journals (Sweden)

Rusalin Lucian R. Păun

2008-05-01

Full Text Available This paper propose a new control technique forsingle – phase AC – AC converters used for a on-line UPSwith a good dynamic response, a reduced-partscomponents, a good output characteristic, a good powerfactorcorrection(PFC. This converter no needs anisolation transformer. A power factor correction rectifierand an inverter with the proposed control scheme has beendesigned and simulated using Caspoc2007, validating theconcept.

Performance of AC/graphite capacitors at high weight ratios of AC/graphite

Energy Technology Data Exchange (ETDEWEB)

Wang, Hongyu [IM and T Ltd., Advanced Research Center, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan); Yoshio, Masaki [Advanced Research Center, Department of Applied Chemistry, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan)

2008-03-01

The effect of negative to positive electrode materials' weight ratio on the electrochemical performance of both activated carbon (AC)/AC and AC/graphite capacitors has been investigated, especially in the terms of capacity and cycle-ability. The limited capacity charge mode has been proposed to improve the cycle performance of AC/graphite capacitors at high weight ratios of AC/graphite. (author)

Novel acsF Gene Primers Revealed a Diverse Phototrophic Bacterial Population, Including Gemmatimonadetes, in Lake Taihu (China)

DEFF Research Database (Denmark)

Huang, Yili; Zeng, Yanhua; Lu, Hang

2016-01-01

Seq sequencing of the 16S rRNA, pufM, and bchY genes was carried out to assess the diversity of local phototrophic communities. In addition, we designed new degenerate primers of aerobic cyclase gene acsF, which serves as a convenient marker for both phototrophic Gemmatimonadetes and phototrophic Proteobacteria...... a diverse community of phototrophic Gemmatimonadetes forming 30 operational taxonomic units. These species represented 10.5 and 17.3% of the acsF reads in the upper semiaerobic sediment and anoxic sediment, whereas their abundance in the water column was ... fundamental biological processes on Earth. Recently, the presence of photosynthetic reaction centers has been reported from a rarely studied bacterial phylum, Gemmatimonadetes, but almost nothing is known about the diversity and environmental distribution of these organisms. The newly designed acsF primers...

Probable alpha and 14C cluster emission from hyper Ac nuclei

International Nuclear Information System (INIS)

Santhosh, K.P.

2013-01-01

A systematic study on the probability for the emission of 4 He and 14 C cluster from hyper Λ 207-234 Ac and non-strange normal 207-234 Ac nuclei are performed for the first time using our fission model, the Coulomb and proximity potential model (CPPM). The predicted half lives show that hyper Λ 207-234 Ac nuclei are unstable against 4 He emission and 14 C emission from hyper Λ 217-228 Ac are favorable for measurement. Our study also show that hyper Λ 207-234 Ac are stable against hyper Λ 4 He and Λ 14 C emission. The role of neutron shell closure (N = 126) in hyper Λ 214 Fr daughter and role of proton/neutron shell closure (Z ∼ 82, N = 126) in hyper Λ 210 Bi daughter are also revealed. As hyper-nuclei decays to normal nuclei by mesonic/non-mesonic decay and since most of the predicted half lives for 4 He and 14 C emission from normal Ac nuclei are favourable for measurement, we presume that alpha and 14 C cluster emission from hyper Ac nuclei can be detected in laboratory in a cascade (two-step) process. (orig.)

The baculovirus core gene ac83 is required for nucleocapsid assembly and per os infectivity of Autographa californica nucleopolyhedrovirus.

Science.gov (United States)

Zhu, Shimao; Wang, Wei; Wang, Yan; Yuan, Meijin; Yang, Kai

2013-10-01

Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac83 is a baculovirus core gene whose function in the AcMNPV life cycle is unknown. In the present study, an ac83-knockout AcMNPV (vAc83KO) was constructed to investigate the function of ac83 through homologous recombination in Escherichia coli. No budded virions were produced in vAc83KO-transfected Sf9 cells, although viral DNA replication was unaffected. Electron microscopy revealed that nucleocapsid assembly was aborted due to the ac83 deletion. Domain-mapping studies revealed that the expression of Ac83 amino acid residues 451 to 600 partially rescued the ability of AcMNPV to produce infectious budded virions. Bioassays indicated that deletion of the chitin-binding domain of Ac83 resulted in the failure of oral infection of Trichoplusia ni larvae by AcMNPV, but AcMNPV remained infectious following intrahemocoelic injection, suggesting that the domain is involved in the binding of occlusion-derived virions to the peritrophic membrane and/or to other chitin-containing insect tissues. It has been demonstrated that Ac83 is the only component with a chitin-binding domain in the per os infectivity factor complex on the occlusion-derived virion envelope. Interestingly, a functional inner nuclear membrane sorting motif, which may facilitate the localization of Ac83 to the envelopes of occlusion-derived virions, was identified by immunofluorescence analysis. Taken together, these results demonstrate that Ac83 plays an important role in nucleocapsid assembly and the establishment of oral infection.

Peltier ac calorimeter

OpenAIRE

Jung, D. H.; Moon, I. K.; Jeong, Y. H.

2001-01-01

A new ac calorimeter, utilizing the Peltier effect of a thermocouple junction as an ac power source, is described. This Peltier ac calorimeter allows to measure the absolute value of heat capacity of small solid samples with sub-milligrams of mass. The calorimeter can also be used as a dynamic one with a dynamic range of several decades at low frequencies.

Here Be Dragons: Characterization of ACS/WFC Scattered Light Anomalies

Science.gov (United States)

Porterfield, B.; Coe, D.; Gonzaga, S.; Anderson, J.; Grogin, N.

2016-11-01

We present a study characterizing scattered light anomalies that occur near the edges of Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) images. We inspected all 8,573 full-frame ACS/WFC raw images with exposure times longer than 350 seconds obtained in the F606W and F814W filters from 2002 to October 2013. We visually identified two particular scattered light artifacts known as "dragon's breath" and edge glow. Using the 2MASS point source catalog and Hubble Guide Star Catalog (GSC II), we identified the stars that caused these artifacts. The stars are all located in narrow bands ( 3" across) just outside the ACS/WFC field of view (2" - 16" away). We provide a map of these risky areas around the ACS/WFC detectors - users should avoid positioning bright stars in these regions when designing ACS/WFC imaging observations. We also provide interactive webpages which display all the image artifacts we identified, allowing users to see examples of the severity of artifacts they might expect for a given stellar magnitude at a given position relative to the ACS/WFC field of view. On average, 10th (18th) magnitude stars produce artifacts about 1,000 (100) pixels long. But the severity of these artifacts can vary strongly with small positional shifts (∼ 1"). The results are similar for both filters (F606W and F814W) when expressed in total fluence, or flux multiplied by exposure time.

Ac-driven vortex-antivortex dynamics in nanostructured superconductor-ferromagnetic hybrids

Energy Technology Data Exchange (ETDEWEB)

Lima, Clessio L.S., E-mail: clsl@df.ufpe.br [Nucleo de Tecnologia, Centro Academico do Agreste, Universidade Federal de Pernambuco, 55002-970 Caruaru-PE (Brazil); Souza Silva, Clecio C. de; Aguiar, J. Albino [Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901 Recife-PE (Brazil)

2012-09-15

The dynamics of ac-driven vortices and antivortices in a superconducting film interacting with an array of magnetic dipoles on top is investigated via hybrid molecular dynamics-Monte Carlo simulations. The dipole array considered in this study is capable to stabilize in equilibrium vortex-antivortex pairs. The appearance of a net electric field out of the ac excitation demonstrates that this system behaves as a voltage rectifier. Because of the asymmetric nature of the effective pinning potential generated by the dipole array, the ac-driven vortices and antivortices are ratcheted in opposite directions, thereby contributing additively to the observed net voltage. In addition, for high frequency values, the dc electric field-ac amplitude curves present a series of steps. A careful analysis of the time series of the electric field and number of vortex-antivortex (v-av) pairs reveals that these steps are related to mode-locking between the drive frequency and the number of v-av creation-annihilation events.

Digital model for harmonic interactions in AC/DC/AC systems

Energy Technology Data Exchange (ETDEWEB)

Guarini, A P; Rangel, R D; Pilotto, L A.S.; Pinto, R J; Passos, Junior, R [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

1994-12-31

The main purpose of this paper is to present a model for calculation of HVdc converter harmonics taking into account the influence of the harmonic interactions between the ac systems in dc link transmissions. The ideas and methodologies used in the model development take into account the dc current ripple and ac voltage distortion in the ac systems. The theory of switching functions is applied to contemplate for the frequency conversions between the ac and dc sides, in an iterative process. It is possible then to obtain, even in balanced situations, non-characteristic harmonics that are produced by frequencies originated in the other terminal, which can be significant in a strongly coupled system, such as back-to-back configuration. (author) 9 refs., 3 figs.

THE GHOSTS SURVEY. I. HUBBLE SPACE TELESCOPE ADVANCED CAMERA FOR SURVEYS DATA

International Nuclear Information System (INIS)

Radburn-Smith, D. J.; Dalcanton, J. J.; De Jong, R. S.; Streich, D.; Vlajic, M.; Seth, A. C.; Bailin, J.; Bell, E. F.; Brown, T. M.; Ferguson, H. C.; Goudfrooij, P.; Holfeltz, S.; Bullock, J. S.; Courteau, S.; Sick, J.; Holwerda, B. W.; Purcell, C.; Zucker, D. B.

2011-01-01

We present an overview of the GHOSTS survey, the largest study to date of the resolved stellar populations in the outskirts of disk galaxies. The sample consists of 14 disk galaxies within 17 Mpc, whose outer disks and halos are imaged with the Hubble Space Telescope Advanced Camera for Surveys (ACS). In the first paper of this series, we describe the sample, explore the benefits of using resolved stellar populations, and discuss our ACS F606W and F814W photometry. We use artificial star tests to assess completeness and use overlapping regions to estimate photometric uncertainties. The median depth of the survey at 50% completeness is 2.7 mag below the tip of the red giant branch (TRGB). We comprehensively explore and parameterize contamination from unresolved background galaxies and foreground stars using archival fields of high-redshift ACS observations. Left uncorrected, these would account for 10 0.65xF814W-19.0 detections per mag per arcsec 2 . We therefore identify several selection criteria that typically remove 95% of the contaminants. Even with these culls, background galaxies are a significant limitation to the surface brightness detection limit which, for this survey, is typically V ∼ 30 mag arcsec -2 . The resulting photometric catalogs are publicly available and contain some 3.1 million stars across 76 ACS fields, predominantly of low extinction. The uniform magnitudes of TRGB stars in these fields enable galaxy distance estimates with 2%-7% accuracy.

The new galaxy evolution paradigm revealed by the Herschel surveys

Science.gov (United States)

Eales, Stephen; Smith, Dan; Bourne, Nathan; Loveday, Jon; Rowlands, Kate; van der Werf, Paul; Driver, Simon; Dunne, Loretta; Dye, Simon; Furlanetto, Cristina; Ivison, R. J.; Maddox, Steve; Robotham, Aaron; Smith, Matthew W. L.; Taylor, Edward N.; Valiante, Elisabetta; Wright, Angus; Cigan, Philip; De Zotti, Gianfranco; Jarvis, Matt J.; Marchetti, Lucia; Michałowski, Michał J.; Phillipps, Steven; Viaene, Sebastien; Vlahakis, Catherine

2018-01-01

The Herschel Space Observatory has revealed a very different galaxyscape from that shown by optical surveys which presents a challenge for galaxy-evolution models. The Herschel surveys reveal (1) that there was rapid galaxy evolution in the very recent past and (2) that galaxies lie on a single Galaxy Sequence (GS) rather than a star-forming 'main sequence' and a separate region of 'passive' or 'red-and-dead' galaxies. The form of the GS is now clearer because far-infrared surveys such as the Herschel ATLAS pick up a population of optically red star-forming galaxies that would have been classified as passive using most optical criteria. The space-density of this population is at least as high as the traditional star-forming population. By stacking spectra of H-ATLAS galaxies over the redshift range 0.001 high stellar masses, high star-formation rates but, even several billion years in the past, old stellar populations - they are thus likely to be relatively recent ancestors of early-type galaxies in the Universe today. The form of the GS is inconsistent with rapid quenching models and neither the analytic bathtub model nor the hydrodynamical EAGLE simulation can reproduce the rapid cosmic evolution. We propose a new gentler model of galaxy evolution that can explain the new Herschel results and other key properties of the galaxy population.

Diode-rectified multiphase AC arc for the improvement of electrode erosion characteristics

Science.gov (United States)

Tanaka, Manabu; Hashizume, Taro; Saga, Koki; Matsuura, Tsugio; Watanabe, Takayuki

2017-11-01

An innovative multiphase AC arc (MPA) system was developed on the basis of a diode-rectification technique to improve electrode erosion characteristics. Conventionally, electrode erosion in AC arc is severer than that in DC arc. This originated from the fact that the required properties for the cathode and anode are different, although an AC electrode works as the cathode and the anode periodically. To solve this problem, a separation of AC electrodes into pairs of thoriated tungsten cathode and copper anode by diode-rectification was attempted. A diode-rectified multiphase AC arc (DRMPA) system was then successfully established, resulting in a drastic improvement of the erosion characteristics. The electrode erosion rate in the DRMPA was less than one-third of that in the conventional MPA without the diode rectification. In order to clarify its erosion mechanism, electrode phenomena during discharge were visualized by a high-speed camera system with appropriate band-pass filters. Fluctuation characteristics of the electrode temperature in the DRMPA were revealed.

ACS Zero Point Verification

Science.gov (United States)

Dolphin, Andrew

2005-07-01

The uncertainties in the photometric zero points create a fundamental limit to the accuracy of photometry. The current state of the ACS calibration is surprisingly poor, with zero point uncertainties of 0.03 magnitudes. The reason for this is that the ACS calibrations are based primarily on semi-emprical synthetic zero points and observations of fields too crowded for accurate ground-based photometry. I propose to remedy this problem by obtaining ACS images of the omega Cen standard field with all nine broadband ACS/WFC filters. This will permit the direct determination of the ACS zero points by comparison with excellent ground-based photometry, and should reduce their uncertainties to less than 0.01 magnitudes. A second benefit is that it will facilitate the comparison of the WFPC2 and ACS photometric systems, which will be important as WFPC2 is phased out and ACS becomes HST's primary imager. Finally, three of the filters will be repeated from my Cycle 12 observations, allowing for a measurement of any change in sensitivity.

Recent Trends in Veteran Unemployment as Measured in the Current Population Survey and the American Community Survey

National Research Council Canada - National Science Library

Savych, Bogdan; Klerman, Jacob A; Loughran, David S

2008-01-01

This technical report explores recent trends in the unemployment of recent veterans as estimated from two nationally representative surveys, the Current Population Survey "CPS" and the American Community Survey "ACS...

A catechol oxidase AcPPO from cherimoya (Annona cherimola Mill.) is localized to the Golgi apparatus.

Science.gov (United States)

Olmedo, Patricio; Moreno, Adrián A; Sanhueza, Dayan; Balic, Iván; Silva-Sanzana, Christian; Zepeda, Baltasar; Verdonk, Julian C; Arriagada, César; Meneses, Claudio; Campos-Vargas, Reinaldo

2018-01-01

Cherimoya (Annona cherimola) is an exotic fruit with attractive organoleptic characteristics. However, it is highly perishable and susceptible to postharvest browning. In fresh fruit, browning is primarily caused by the polyphenol oxidase (PPO) enzyme catalyzing the oxidation of o-diphenols to quinones, which polymerize to form brown melanin pigment. There is no consensus in the literature regarding a specific role of PPO, and its subcellular localization in different plant species is mainly described within plastids. The present work determined the subcellular localization of a PPO protein from cherimoya (AcPPO). The obtained results revealed that the AcPPO- green fluorescent protein co-localized with a Golgi apparatus marker, and AcPPO activity was present in Golgi apparatus-enriched fractions. Likewise, transient expression assays revealed that AcPPO remained active in Golgi apparatus-enriched fractions obtained from tobacco leaves. These results suggest a putative function of AcPPO in the Golgi apparatus of cherimoya, providing new perspectives on PPO functionality in the secretory pathway, its effects on cherimoya physiology, and the evolution of this enzyme. Copyright © 2017. Published by Elsevier B.V.

Abscisic Acid Antagonizes Ethylene Production through the ABI4-Mediated Transcriptional Repression of ACS4 and ACS8 in Arabidopsis.

Science.gov (United States)

Dong, Zhijun; Yu, Yanwen; Li, Shenghui; Wang, Juan; Tang, Saijun; Huang, Rongfeng

2016-01-04

Increasing evidence has revealed that abscisic acid (ABA) negatively modulates ethylene biosynthesis, although the underlying mechanism remains unclear. To identify the factors involved, we conducted a screen for ABA-insensitive mutants with altered ethylene production in Arabidopsis. A dominant allele of ABI4, abi4-152, which produces a putative protein with a 16-amino-acid truncation at the C-terminus of ABI4, reduces ethylene production. By contrast, two recessive knockout alleles of ABI4, abi4-102 and abi4-103, result in increased ethylene evolution, indicating that ABI4 negatively regulates ethylene production. Further analyses showed that expression of the ethylene biosynthesis genes ACS4, ACS8, and ACO2 was significantly decreased in abi4-152 but increased in the knockout mutants, with partial dependence on ABA. Chromatin immunoprecipitation-quantitative PCR assays showed that ABI4 directly binds the promoters of these ethylene biosynthesis genes and that ABA enhances this interaction. A fusion protein containing the truncated ABI4-152 peptide accumulated to higher levels than its full-length counterpart in transgenic plants, suggesting that ABI4 is destabilized by its C terminus. Therefore, our results demonstrate that ABA negatively regulates ethylene production through ABI4-mediated transcriptional repression of the ethylene biosynthesis genes ACS4 and ACS8 in Arabidopsis. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

Low Offset AC Correlator.

Science.gov (United States)

This patent describes a low offset AC correlator avoids DC offset and low frequency noise by frequency operating the correlation signal so that low...noise, low level AC amplification can be substituted for DC amplification. Subsequently, the high level AC signal is demodulated to a DC level. (Author)

AC power supply systems

International Nuclear Information System (INIS)

Law, H.

1987-01-01

An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

VizieR Online Data Catalog: HST/ACS Coma cluster survey. II. (Hammer+, 2010)

NARCIS (Netherlands)

Hammer, D.; Verdoes Kleijn, G.; Hoyos, C.; den Brok, M.; Balcells, M.; Ferguson, H. C.; Goudfrooij, P.; Carter, D.; Guzman, R.; Peletier, R. F.; Smith, R. J.; Graham, A. W.; Trentham, N.; Peng, E.; Puzia, T. H.; Lucey, J. R.; Jogee, S.; Aguerri, A. L.; Batcheldor, D.; Bridges, T. J.; Chiboucas, K.; Davies, J. I.; Del Burgo, C.; Erwin, P.; Hornschemeier, A.; Hudson, M. J.; Huxor, A.; Jenkins, L.; Karick, A.; Khosroshahi, H.; Kourkchi, E.; Komiyama, Y.; Lotz, J.; Marzke, R. O.; Marinova, I.; Matkovic, A.; Merritt, D.; Miller, B. W.; Miller, N. A.; Mobasher, B.; Mouhcine, M.; Okamura, S.; Percival, S.; Phillipps, S.; Poggianti, B. M.; Price, J.; Sharples, R. M.; Tully, R. B.; Valentijn, E.

2010-01-01

This data release contains catalogs for the ACS Images in F475W and F814W bands of 25 fields in the Coma cluster of galaxies. Each field is about 202x202arcsec. Please see the release notes for further details. (25 data files).

Replacing the IRAF/PyRAF Code-base at STScI: The Advanced Camera for Surveys (ACS)

Science.gov (United States)

Lucas, Ray A.; Desjardins, Tyler D.; STScI ACS (Advanced Camera for Surveys) Team

2018-06-01

IRAF/PyRAF are no longer viable on the latest hardware often used by HST observers, therefore STScI no longer actively supports IRAF or PyRAF for most purposes. STScI instrument teams are in the process of converting all of our data processing and analysis code from IRAF/PyRAF to Python, including our calibration reference file pipelines and data reduction software. This is exemplified by our latest ACS Data Handbook, version 9.0, which was recently published in February 2018. Examples of IRAF and PyRAF commands have now been replaced by code blocks in Python, with references linked to documentation on how to download and install the latest Python software via Conda and AstroConda. With the temporary exception of the ACS slitless spectroscopy tool aXe, all ACS-related software is now independent of IRAF/PyRAF. A concerted effort has been made across STScI divisions to help the astronomical community transition from IRAF/PyRAF to Python, with tools such as Python Jupyter notebooks being made to give users workable examples. In addition to our code changes, the new ACS data handbook discusses the latest developments in charge transfer efficiency (CTE) correction, bias de-striping, and updates to the creation and format of calibration reference files among other topics.

ACS Photometric Zero Point Verification

Science.gov (United States)

Dolphin, Andrew

2003-07-01

The uncertainties in the photometric zero points create a fundamental limit to the accuracy of photometry. The current state of the ACS calibration is surprisingly poor, with zero point uncertainties of 0.03 magnitudes in the Johnson filters. The reason for this is that ACS observations of excellent ground-based standard fields, such as the omega Cen field used for WFPC2 calibrations, have not been obtained. Instead, the ACS photometric calibrations are based primarily on semi-emprical synthetic zero points and observations of fields too crowded for accurate ground-based photometry. I propose to remedy this problem by obtaining ACS broadband images of the omega Cen standard field with both the WFC and HRC. This will permit the direct determination of the ACS transformations, and is expected to double the accuracy to which the ACS zero points are known. A second benefit is that it will facilitate the comparison of the WFPC2 and ACS photometric systems, which will be important as WFPC2 is phased out and ACS becomes HST's primary imager.

Accounting for Dark Current Accumulated during Readout of Hubble's ACS/WFC Detectors

Science.gov (United States)

Ryon, Jenna E.; Grogin, Norman A.; Coe, Dan A.; ACS Team

2018-06-01

We investigate the properties of excess dark current accumulated during the 100-second full-frame readout of the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) detectors. This excess dark current, called "readout dark", gives rise to ambient background gradients and hot columns in each ACS/WFC image. While readout dark signal is removed from science images during the bias correction step in CALACS, the additional noise from the readout dark is currently not taken into account. We develop a method to estimate the readout dark noise properties in ACS/WFC observations. We update the error (ERR) extensions of superbias images to include the appropriate noise from the ambient readout dark gradient and stable hot columns. In recent data, this amounts to about 5 e-/pixel added variance in the rows farthest from the WFC serial registers, and about 7 to 30 e-/pixel added variance along the stable hot columns. We also flag unstable hot columns in the superbias data quality (DQ) extensions. The new reference file pipeline for ACS/WFC implements these updates to our superbias creation process.

THE ACS FORNAX CLUSTER SURVEY. IV. DEPROJECTION OF THE SURFACE BRIGHTNESS PROFILES OF EARLY-TYPE GALAXIES IN THE VIRGO AND FORNAX CLUSTERS: INVESTIGATING THE 'CORE/POWER-LAW DICHOTOMY'

International Nuclear Information System (INIS)

Glass, Lisa; Ferrarese, Laura; Cote, Patrick; Blakeslee, John P.; Chen, Chin-Wei; Jordan, Andres; Infante, Leopoldo; Peng, Eric; Mei, Simona; Tonry, John L.; West, Michael J.

2011-01-01

Although early observations with the Hubble Space Telescope (HST) pointed to a sharp dichotomy among early-type galaxies in terms of the logarithmic slope γ' of their central surface brightness profiles, several studies in the past few years have called this finding into question. In particular, recent imaging surveys of 143 early-type galaxies belonging to the Virgo and Fornax Clusters using the Advanced Camera for Surveys (ACS) on board HST have not found a dichotomy in γ', but instead a systematic progression from central luminosity deficit to excess relative to the inward extrapolation of the best-fitting global Sersic model. Given that earlier studies also found that the dichotomy persisted when analyzing the deprojected density profile slopes, we investigate the distribution of the three-dimensional luminosity density profiles of the ACS Virgo and Fornax Cluster Survey galaxies. Having fitted the surface brightness profiles with modified Sersic models, we then deproject the galaxies using an Abel integral and measure the inner slopes γ 3D of the resulting luminosity density profiles at various fractions of the effective radius R e . We find no evidence of a dichotomy, but rather, a continuous variation in the central luminosity profiles as a function of galaxy magnitude. We introduce a parameter, Δ 3D , that measures the central deviation of the deprojected luminosity profiles from the global Sersic fit, showing that this parameter varies smoothly and systematically along the luminosity function.

THE HST EXTREME DEEP FIELD (XDF): COMBINING ALL ACS AND WFC3/IR DATA ON THE HUDF REGION INTO THE DEEPEST FIELD EVER

International Nuclear Information System (INIS)

Illingworth, G. D.; Magee, D.; Oesch, P. A.; Bouwens, R. J.; Labbé, I.; Franx, M.; Stiavelli, M.; Van Dokkum, P. G.; Trenti, M.; Carollo, C. M.; Gonzalez, V.

2013-01-01

The eXtreme Deep Field (XDF) combines data from 10 years of observations with the Hubble Space Telescope Advanced Camera for Surveys (ACS) and the Wide-Field Camera 3 Infra-Red (WFC3/IR) into the deepest image of the sky ever in the optical/near-IR. Since the initial observations of the Hubble Ultra-Deep Field (HUDF) in 2003, numerous surveys and programs, including supernovae follow-up, HUDF09, CANDELS, and HUDF12, have contributed additional imaging data across this region. However, these images have never been combined and made available as one complete ultra-deep image dataset. We combine them now with the XDF program. Our new and improved processing techniques provide higher quality reductions of the total dataset. All WFC3/IR and optical ACS data sets have been fully combined and accurately matched, resulting in the deepest imaging ever taken at these wavelengths, ranging from 29.1 to 30.3 AB mag (5σ in a 0.''35 diameter aperture) in 9 filters. The combined image therefore reaches to 31.2 AB mag 5σ (32.9 at 1σ) for a flat f ν source. The gains in the optical for the four filters done in the original ACS HUDF correspond to a typical improvement of 0.15 mag, with gains of 0.25 mag in the deepest areas. Such gains are equivalent to adding ∼130 to ∼240 orbits of ACS data to the HUDF. Improved processing alone results in a typical gain of ∼0.1 mag. Our 5σ (optical+near-IR) SExtractor catalogs reveal about 14,140 sources in the full field and about 7121 galaxies in the deepest part of the XDF

FLUIDIC AC AMPLIFIERS.

Science.gov (United States)

Several fluidic tuned AC Amplifiers were designed and tested. Interstage tuning and feedback designs are considered. Good results were obtained...corresponding Q’s as high as 12. Element designs and test results of one, two, and three stage amplifiers are presented. AC Modulated Carrier Systems

78 FR 49318 - Availability of Draft Advisory Circular (AC) 90-106A and AC 20-167A

Science.gov (United States)

2013-08-13

...] Availability of Draft Advisory Circular (AC) 90-106A and AC 20- 167A AGENCY: Federal Aviation Administration... of draft Advisory Circular (AC) 90-106A, Enhanced Flight Vision Systems and draft AC 20- 167A... Federal holidays. FOR FURTHER INFORMATION CONTACT: For technical questions concerning draft AC 90-106A...

Molecular and functional characterization of CpACS27A gene reveals its involvement in monoecy instability and other associated traits in squash (Cucurbita pepo L.).

Science.gov (United States)

Martínez, Cecilia; Manzano, Susana; Megías, Zoraida; Barrera, Alejandro; Boualem, Adnane; Garrido, Dolores; Bendahmane, Abdelhafid; Jamilena, Manuel

2014-06-01

A number of Cucurbita pepo genotypes showing instable monoecy or partial andromonoecy, i.e. an incomplete conversion of female into bisexual flowers, have been detected. Given that in melon and cucumber andromonoecy is the result of reduction of ethylene production in female floral buds, caused by mutations in the ethylene biosynthesis genes CmACS7 and CsACS2; we have cloned and characterized two related C. pepo genes, CpACS27A and CpACS27B. The molecular structure of CpACS27A and its specific expression in the carpels of female flowers during earlier stages of flower development suggests that this gene is the Cucurbita ortholog of CmACS7 and CsACS2. CpACS27B is likely to be a paralogous pseudogene since it has not been found to be expressed in any of the analyzed tissues. CpACS27A was sequenced in Bolognese (Bog) and Vegetable Spaghetti (Veg), two monoecious inbred lines whose F2 was segregating for partial andromonoecy. The Bog allele of CpACS27A carried a missense mutation that resulted in a substitution of the conserved serine residue in position 176 by an alanine. Segregation analysis indicated that this mutant variant is necessary but not sufficient to confer the andromonoecious phenotype in squash. In concordance with its involvement in stamen arrest, a reduction in CpACS27A expression has been found in bisexual flower buds at earlier stages of development. This reduction in CpACS27A expression was concomitant with a downregulation of other ethylene biosynthesis and signaling genes during earlier and later stages of ovary development. The role of CpACS27A is discussed regarding the regulation of ethylene biosynthesis and signaling genes in the control of andromonoecy-associated traits, such as the delayed maturation of corolla and stigma as well as the parthenocarpic development of the fruit.

Deletion of the AcMNPV core gene ac109 results in budded virions that are non-infectious

International Nuclear Information System (INIS)

Fang Minggang; Nie, Yingchao; Theilmann, David A.

2009-01-01

Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac109 is a core gene and its function in the virus life cycle is unknown. To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac109 deletion virus (vAc 109KO ). Fluorescence and light microscopy showed that transfection of vAc 109KO results in a single-cell infection phenotype. Viral DNA replication is unaffected and the development of occlusion bodies in vAc 109KO -transfected cells evidenced progression to the very late phases of viral infection. Western blot and confocal immunofluorescence analysis showed that AC109 is expressed in the cytoplasm and nucleus throughout infection. In addition, AC109 is a structural protein as it was detected in both budded virus (BV) and occlusion derived virus in both the envelope and nucleocapsid fractions. Titration assays by qPCR and TCID 50 showed that vAc 109KO produced BV but the virions are non-infectious. The vAc 109KO BV were indistinguishable from the BV of repaired and wild type control viruses as determined by negative staining and electron microscopy.

Development of a hardware-based AC microgrid for AC stability assessment

Science.gov (United States)

Swanson, Robert R.

As more power electronic-based devices enable the development of high-bandwidth AC microgrids, the topic of microgrid power distribution stability has become of increased interest. Recently, researchers have proposed a relatively straightforward method to assess the stability of AC systems based upon the time-constants of sources, the net bus capacitance, and the rate limits of sources. In this research, a focus has been to develop a hardware test system to evaluate AC system stability. As a first step, a time domain model of a two converter microgrid was established in which a three phase inverter acts as a power source and an active rectifier serves as an adjustable constant power AC load. The constant power load can be utilized to create rapid power flow transients to the generating system. As a second step, the inverter and active rectifier were designed using a Smart Power Module IGBT for switching and an embedded microcontroller as a processor for algorithm implementation. The inverter and active rectifier were designed to operate simultaneously using a synchronization signal to ensure each respective local controller operates in a common reference frame. Finally, the physical system was created and initial testing performed to validate the hardware functionality as a variable amplitude and variable frequency AC system.

Management of Periprocedural Anticoagulation: A Survey of Contemporary Practice.

Science.gov (United States)

Flaker, Greg C; Theriot, Paul; Binder, Lea G; Dobesh, Paul P; Cuker, Adam; Doherty, John U

2016-07-12

Interruption of oral anticoagulation (AC) for surgery or an invasive procedure is a complicated process. Practice guidelines provide only general recommendations, and care of such patients occurs across multiple specialties. The availability of direct oral anticoagulants further complicates decision making and guidance here is limited. To evaluate current practice patterns in the United States for bridging AC, a survey was developed by the American College of Cardiology Anticoagulation Work Group. The goal of the survey was to assess how general and subspecialty cardiologists, internists, gastroenterologists, and orthopedic surgeons currently manage patients who receive AC and undergo surgery or an invasive procedure. The survey was completed by 945 physicians involved in the periprocedural management of AC. The results provide a template for educational and research projects geared toward the development of clinical pathways and point-of-care tools to improve this area of health care. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

76 FR 12935 - Proposed Information Collection; Comment Request; The American Community Survey

Science.gov (United States)

2011-03-09

... developed the American Community Survey (ACS). This survey collects detailed population and housing data..., economic, and housing characteristics. The ACS provides more timely information for critical economic planning by governments and the private sector. In the current information-based economy, federal, state...

Estimating BrAC from transdermal alcohol concentration data using the BrAC estimator software program.

Science.gov (United States)

Luczak, Susan E; Rosen, I Gary

2014-08-01

Transdermal alcohol sensor (TAS) devices have the potential to allow researchers and clinicians to unobtrusively collect naturalistic drinking data for weeks at a time, but the transdermal alcohol concentration (TAC) data these devices produce do not consistently correspond with breath alcohol concentration (BrAC) data. We present and test the BrAC Estimator software, a program designed to produce individualized estimates of BrAC from TAC data by fitting mathematical models to a specific person wearing a specific TAS device. Two TAS devices were worn simultaneously by 1 participant for 18 days. The trial began with a laboratory alcohol session to calibrate the model and was followed by a field trial with 10 drinking episodes. Model parameter estimates and fit indices were compared across drinking episodes to examine the calibration phase of the software. Software-generated estimates of peak BrAC, time of peak BrAC, and area under the BrAC curve were compared with breath analyzer data to examine the estimation phase of the software. In this single-subject design with breath analyzer peak BrAC scores ranging from 0.013 to 0.057, the software created consistent models for the 2 TAS devices, despite differences in raw TAC data, and was able to compensate for the attenuation of peak BrAC and latency of the time of peak BrAC that are typically observed in TAC data. This software program represents an important initial step for making it possible for non mathematician researchers and clinicians to obtain estimates of BrAC from TAC data in naturalistic drinking environments. Future research with more participants and greater variation in alcohol consumption levels and patterns, as well as examination of gain scheduling calibration procedures and nonlinear models of diffusion, will help to determine how precise these software models can become. Copyright © 2014 by the Research Society on Alcoholism.

Indoor Air Pollution in Non Ac Passenger Bus

Science.gov (United States)

El Husna, Iksiroh; Unzilatirrizqi, Rizal D. Yan El; Karyanto, Yudi; Sunoko, Henna R.

2018-02-01

Passenger buses have been one of favorite means of transportation in Indonesia due to its affordability and flexibility. Intensity of human activities during the trip in the buses have a potential of causing indoor air pollution (polusi udara dalam ruang; PUDR). The indoor air pollution has an impact of 1000-time bigger than outdoor air pollution (polusi udara luar ruang; PULR) on lung. This study aimed to find out indoor air pollution rate of non air conditioned buses using an approach to biological agent pollutant source. The study applied an analysis restricted to microorganisms persistence as one of the sources of the indoor air pollution. The media were placed in different parts of the non AC buses. This study revealed that fungs were found in the non AC buses. They became contaminants and developed pathogenic bacteria that caused air pollution.

Indoor Air Pollution in Non Ac Passenger Bus

Directory of Open Access Journals (Sweden)

El Husna Iksiroh

2018-01-01

Full Text Available Passenger buses have been one of favorite means of transportation in Indonesia due to its affordability and flexibility. Intensity of human activities during the trip in the buses have a potential of causing indoor air pollution (polusi udara dalam ruang; PUDR. The indoor air pollution has an impact of 1000-time bigger than outdoor air pollution (polusi udara luar ruang; PULR on lung. This study aimed to find out indoor air pollution rate of non air conditioned buses using an approach to biological agent pollutant source. The study applied an analysis restricted to microorganisms persistence as one of the sources of the indoor air pollution. The media were placed in different parts of the non AC buses. This study revealed that fungs were found in the non AC buses. They became contaminants and developed pathogenic bacteria that caused air pollution.

Early function of the Abutilon mosaic virus AC2 gene as a replication brake.

Science.gov (United States)

Krenz, Björn; Deuschle, Kathrin; Deigner, Tobias; Unseld, Sigrid; Kepp, Gabi; Wege, Christina; Kleinow, Tatjana; Jeske, Holger

2015-04-01

The C2/AC2 genes of monopartite/bipartite geminiviruses of the genera Begomovirus and Curtovirus encode important pathogenicity factors with multiple functions described so far. A novel function of Abutilon mosaic virus (AbMV) AC2 as a replication brake is described, utilizing transgenic plants with dimeric inserts of DNA B or with a reporter construct to express green fluorescent protein (GFP). Their replicational release upon AbMV superinfection or the individual and combined expression of epitope-tagged AbMV AC1, AC2, and AC3 was studied. In addition, the effects were compared in the presence and in the absence of an unrelated tombusvirus suppressor of silencing (P19). The results show that AC2 suppresses replication reproducibly in all assays and that AC3 counteracts this effect. Examination of the topoisomer distribution of supercoiled DNA, which indicates changes in the viral minichromosome structure, did not support any influence of AC2 on transcriptional gene silencing and DNA methylation. The geminiviral AC2 protein has been detected here for the first time in plants. The experiments revealed an extremely low level of AC2, which was slightly increased if constructs with an intron and a hemagglutinin (HA) tag in addition to P19 expression were used. AbMV AC2 properties are discussed with reference to those of other geminiviruses with respect to charge, modification, and size in order to delimit possible reasons for the different behaviors. The (A)C2 genes encode a key pathogenicity factor of begomoviruses and curtoviruses in the plant virus family Geminiviridae. This factor has been implicated in the resistance breaking observed in agricultural cotton production. AC2 is a multifunctional protein involved in transcriptional control, gene silencing, and regulation of basal biosynthesis. Here, a new function of Abutilon mosaic virus AC2 in replication control is added as a feature of this protein in viral multiplication, providing a novel finding on

RHIC spin flipper AC dipole controller

Energy Technology Data Exchange (ETDEWEB)

Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

2011-03-28

The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

A Ser/Thr protein kinase phosphorylates MA-ACS1 (Musa acuminata 1-aminocyclopropane-1-carboxylic acid synthase 1) during banana fruit ripening.

Science.gov (United States)

Choudhury, Swarup Roy; Roy, Sujit; Sengupta, Dibyendu N

2012-08-01

1-Aminocyclopropane-1-carboxylic acid synthase (ACS) catalyzes the rate-limiting step in ethylene biosynthesis during ripening. ACS isozymes are regulated both transcriptionally and post-translationally. However, in banana, an important climacteric fruit, little is known about post-translational regulation of ACS. Here, we report the post-translational modification of MA-ACS1 (Musa acuminata ACS1), a ripening inducible isozyme in the ACS family, which plays a key role in ethylene biosynthesis during banana fruit ripening. Immunoprecipitation analyses of phospholabeled protein extracts from banana fruit using affinity-purified anti-MA-ACS1 antibody have revealed phosphorylation of MA-ACS1, particularly in ripe fruit tissue. We have identified the induction of a 41-kDa protein kinase activity in pulp at the onset of ripening. The 41-kDa protein kinase has been identified as a putative protein kinase by MALDI-TOF/MS analysis. Biochemical analyses using partially purified protein kinase fraction from banana fruit have identified the protein kinase as a Ser/Thr family of protein kinase and its possible involvement in MA-ACS1 phosphorylation during ripening. In vitro phosphorylation analyses using synthetic peptides and site-directed mutagenized recombinant MA-ACS1 have revealed that serine 476 and 479 residues at the C-terminal region of MA-ACS1 are phosphorylated. Overall, this study provides important novel evidence for in vivo phosphorylation of MA-ACS1 at the molecular level as a possible mechanism of post-translational regulation of this key regulatory protein in ethylene signaling pathway in banana fruit during ripening.

Study of a twisted ATLAS SCT Barrel deformation as revealed by a photogrammetric survey

CERN Document Server

Dobson, E; Heinemann, F; Karagoz-Unel, M

2007-01-01

A photogrammetry survey on the SCT barrels was performed as an engineering check on the structure of the ATLAS Semiconductor Tracker (SCT) shortly after construction. Analysis of the data obtained revealed small scale elliptical deformation as well as a twist of the structure. The results of the survey are presented as well as interpolation of the measured targets to the module positions and a comparison with track based alignment measurements.

The AC photovoltaic module is here!

Science.gov (United States)

Strong, Steven J.; Wohlgemuth, John H.; Wills, Robert H.

1997-02-01

This paper describes the design, development, and performance results of a large-area photovoltaic module whose electrical output is ac power suitable for direct connection to the utility grid. The large-area ac PV module features a dedicated, integrally mounted, high-efficiency dc-to-ac power inverter with a nominal output of 250 watts (STC) at 120 Vac, 60 H, that is fully compatible with utility power. The module's output is connected directly to the building's conventional ac distribution system without need for any dc wiring, string combiners, dc ground-fault protection or additional power-conditioning equipment. With its advantages, the ac photovoltaic module promises to become a universal building block for use in all utility-interactive PV systems. This paper discusses AC Module design aspects and utility interface issues (including islanding).

Levitação acústica

OpenAIRE

Andrade, Marco Aurélio Brizzotti; Pérez, Nicolás; Adamowski, Julio Cezar

2015-01-01

A levitação acústica pode ser uma ferramenta valiosa para auxiliar estudantes de graduação a aprender conceitos básicos de física, tais como movimento harmônico simples, ondas acústicas estacionárias, e energia potencial. Neste artigo, apresentamos o princípio de funcionamento de um levitador acústico e explicamos como aplicar as equações básicas da acústica para determinar a força de radiação acústica que atua numa esfera em uma onda estacionária. Acoustic levitation can be a valuable too...

Autographa californica multiple nucleopolyhedrovirus ac66 is required for the efficient egress of nucleocapsids from the nucleus, general synthesis of preoccluded virions and occlusion body formation

International Nuclear Information System (INIS)

Ke Jianhao; Wang Jinwen; Deng Riqiang; Wang Xunzhang

2008-01-01

Although orf66 (ac66) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is conserved in all sequenced lepidopteran baculovirus genomes, its function is not known. This paper describes generation of an ac66 knockout AcMNPV bacmid mutant and analyses of the influence of ac66 deletion on the virus replication in Sf-9 cells so as to determine the role of ac66 in the viral life cycle. Results indicated that budded virus (BV) yields were reduced over 99% in ac66-null mutant infected cells in comparison to that in wild-type virus infected cells. Optical microscopy revealed that occlusion body synthesis was significantly reduced in the ac66 knockout bacmid-transfected cells. In addition, ac66 deletion interrupted preoccluded virion synthesis. The mutant phenotype was rescued by an ac66 repair bacmid. On the other hand, real-time PCR analysis indicated that ac66 deletion did not affect the levels of viral DNA replication. Electron microscopy revealed that ac66 is not essential for nucleocapsid assembly, but for the efficient transport of nucleocapsids from the nucleus to the cytoplasm. These results suggested that ac66 plays an important role for the efficient exit of nucleocapsids from the nucleus to the cytoplasm for BV synthesis as well as for preoccluded virion and occlusion synthesis

Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

DEFF Research Database (Denmark)

Ljusev, Petar; Andersen, Michael Andreas E.

2004-01-01

This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion...

Introduction to AC machine design

CERN Document Server

Lipo, Thomas A

2018-01-01

AC electrical machine design is a key skill set for developing competitive electric motors and generators for applications in industry, aerospace, and defense. This book presents a thorough treatment of AC machine design, starting from basic electromagnetic principles and continuing through the various design aspects of an induction machine. Introduction to AC Machine Design includes one chapter each on the design of permanent magnet machines, synchronous machines, and thermal design. It also offers a basic treatment of the use of finite elements to compute the magnetic field within a machine without interfering with the initial comprehension of the core subject matter. Based on the author's notes, as well as after years of classroom instruction, Introduction to AC Machine Design: * Brings to light more advanced principles of machine design--not just the basic principles of AC and DC machine behavior * Introduces electrical machine design to neophytes while also being a resource for experienced designers * ...

The Effect of the Feedback Controller on Superconducting Tokamak AC Losses + AC-CRPP user manual

International Nuclear Information System (INIS)

Schaerz, B.; Bruzzone, P.; Favez, J.Y.; Lister, J.B.; Zapretilina, E.

2001-11-01

Superconducting coils in a Tokamak are subject to AC losses when the field transverse to the coil current varies. A simple model to evaluate the AC losses has been derived and benchmarked against a complete model used in the ITER design procedure. The influence of the feedback control strategy on the AC losses is examined using this model. An improved controller is proposed, based on this study. (author)

AcMNPV ac143 (odv-e18) is essential for mediating budded virus production and is the 30th baculovirus core gene

International Nuclear Information System (INIS)

McCarthy, Christina B.; Theilmann, David A.

2008-01-01

Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac143 (odv-e18) is a late gene that encodes for a predicted 9.6 kDa structural protein that locates to the occlusion derived viral envelope and viral induced intranuclear microvesicles [Braunagel, S.C., He, H., Ramamurthy, P., and Summers, M.D. (1996). Transcription, translation, and cellular localization of three Autographa californica nuclear polyhedrosis virus structural proteins: ODV-E18, ODV-E35, and ODV-EC27. Virology 222, 100-114.]. In this study we demonstrate that ac143 is actually a previously unrecognized core gene and that it is essential for mediating budded virus production. To examine the role of ac143 in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac143 knockout (KO) virus (AcBAC ac142REP-ac143KO ). Fluorescence and light microscopy showed that infection by AcBAC ac142REP-ac143KO is limited to a single cell and titration assays confirmed that AcBAC ac142REP-ac143KO was unable to produce budded virus (BV). Progression to very late phases of the viral infection was evidenced by the development of occlusion bodies in the nuclei of transfected cells. This correlated with the fact that viral DNA replication was unaffected in AcBAC ac142REP-ac143KO transfected cells. The entire ac143 promoter, which includes three late promoter motifs, is contained within the ac142 open reading frame. Different deletion mutants of this region showed that the integrity of the ac142-ac143 core gene cluster was required for the bacmids to display wild-type patterns of viral replication, BV production and RNA transcription

Expression of hybrid fusion protein (Cry1Ac::ASAL) in transgenic rice plants imparts resistance against multiple insect pests.

Science.gov (United States)

Boddupally, Dayakar; Tamirisa, Srinath; Gundra, Sivakrishna Rao; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

2018-05-31

To evolve rice varieties resistant to different groups of insect pests a fusion gene, comprising DI and DII domains of Bt Cry1Ac and carbohydrate binding domain of garlic lectin (ASAL), was constructed. Transgenic rice lines were generated and evaluated to assess the efficacy of Cry1Ac::ASAL fusion protein against three major pests, viz., yellow stem borer (YSB), leaf folder (LF) and brown planthopper (BPH). Molecular analyses of transgenic plants revealed stable integration and expression of the fusion gene. In planta insect bioassays on transgenics disclosed enhanced levels of resistance compared to the control plants. High insect mortality of YSB, LF and BPH was observed on transgenics compared to that of control plants. Furthermore, honeydew assays revealed significant decreases in the feeding ability of BPH on transgenic plants as compared to the controls. Ligand blot analysis, using BPH insects fed on cry1Ac::asal transgenic rice plants, revealed a modified receptor protein-binding pattern owing to its ability to bind to additional receptors in insects. The overall results authenticate that Cry1Ac::ASAL protein is endowed with remarkable entomotoxic effects against major lepidopteran and hemipteran insects. As such, the fusion gene appears promising and can be introduced into various other crops to control multiple insect pests.

Innovative application of AC-voltammetry in the characterization of oxides nanolayers formed on metals, under the effect of AC-perturbations

Energy Technology Data Exchange (ETDEWEB)

Bueno, V.; Lazzari, L.; Ormellesse, M. [Politecnico di Milano, Milan (Italy). Dept. of Chemistry, Materials and Chemical Engineering; Spinelli, P. [Politecnico di Torino, Torino (Italy). Dept. of Materials Science and Chemical Engineering

2008-07-01

Stray AC-currents have been reported to cause many cases of unwanted corrosion on metallic structures. This study characterized the formation and stability of the surface oxide film formed on mild steel under the effect of AC voltage in a very basic environment. The response of the system to DC signals was examined, along with its reversibility to AC perturbations. SEM analysis was used to complement AC-Voltammetry. Reaction mechanisms responsible for the AC-corrosion were formulated. AC-Voltammetry involves the application of a controlled sinusoidal voltage onto a solid working electrode while it is being swept in a DC-voltage range, with the faradaic or capacitative components of the resulting AC-current being recorded. The innovative aspect is the application of AC-V to characterize its nano-surface while it is being affected by AC-signals. It was concluded that the AC-V can be useful for the study of redox processes occurring at the surface of a reactive electrode and for the application of a considerable AC perturbation to the electrode in a potentiostatically controlled way. According to the electrochemistry of the double layer, there are 3 main reactions in the NaOH 1M media that are not reversible to DC nor to AC perturbations in the range of cathodic protection of mild steel. When designing metallic systems susceptible to stray currents, the AC-V could quantify the final faradaic, resistive and capacitative responses. 6 refs., 1 fig.

High voltage AC/AC electrochemical capacitor operating at low temperature in salt aqueous electrolyte

Science.gov (United States)

Abbas, Qamar; Béguin, François

2016-06-01

We demonstrate that an activated carbon (AC)-based electrochemical capacitor implementing aqueous lithium sulfate electrolyte in 7:3 vol:vol water/methanol mixture can operate down to -40 °C with good electrochemical performance. Three-electrode cell investigations show that the faradaic contributions related with hydrogen chemisorption in the negative AC electrode are thermodynamically unfavored at -40 °C, enabling the system to work as a typical electrical double-layer (EDL) capacitor. After prolonged floating of the AC/AC capacitor at 1.6 V and -40°C, the capacitance, equivalent series resistance and efficiency remain constant, demonstrating the absence of ageing related with side redox reactions at this temperature. Interestingly, when temperature is increased back to 24 °C, the redox behavior due to hydrogen storage reappears and the system behaves as a freshly prepared one.

AcEST: DK954361 [AcEST

Lifescience Database Archive (English)

Full Text Available in 5-4 OS=Homo sap... 33 1.1 sp|Q9DBY1|SYVN1_MOUSE E3 ubiquitin-protein ligase synoviolin OS=... 33 1.4 sp|Q...86TM6|SYVN1_HUMAN E3 ubiquitin-protein ligase synoviolin OS=... 33 1.4 sp|O55188|DMP1_MOUSE Dentin matrix ac

21 CFR 886.4440 - AC-powered magnet.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove...

The Effects of the Toxic Cyanobacterium Limnothrix (Strain AC0243 on Bufo marinus Larvae

Directory of Open Access Journals (Sweden)

Olivia Daniels

2014-03-01

Full Text Available Limnothrix (strain AC0243 is a cyanobacterium, which has only recently been identified as toxin producing. Under laboratory conditions, Bufo marinus larvae were exposed to 100,000 cells mL−1 of Limnothrix (strain AC0243 live cultures for seven days. Histological examinations were conducted post mortem and revealed damage to the notochord, eyes, brain, liver, kidney, pancreas, gastrointestinal tract, and heart. The histopathological results highlight the toxicological impact of this strain, particularly during developmental stages. Toxicological similarities to β-N-Methylamino-L-alanine are discussed.

The Effects of the Toxic Cyanobacterium Limnothrix (Strain AC0243) on Bufo marinus Larvae

Science.gov (United States)

Daniels, Olivia; Fabbro, Larelle; Makiela, Sandrine

2014-01-01

Limnothrix (strain AC0243) is a cyanobacterium, which has only recently been identified as toxin producing. Under laboratory conditions, Bufo marinus larvae were exposed to 100,000 cells mL−1 of Limnothrix (strain AC0243) live cultures for seven days. Histological examinations were conducted post mortem and revealed damage to the notochord, eyes, brain, liver, kidney, pancreas, gastrointestinal tract, and heart. The histopathological results highlight the toxicological impact of this strain, particularly during developmental stages. Toxicological similarities to β-N-Methylamino-l-alanine are discussed. PMID:24662524

Simultaneous distribution of AC and DC power

Science.gov (United States)

Polese, Luigi Gentile

2015-09-15

A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

Isolation of MA-ACS Gene Family and Expression Study of MA-ACS1 Gene in Musa acuminata Cultivar Pisang Ambon Lumut

Directory of Open Access Journals (Sweden)

LISTYA UTAMI KARMAWAN

2009-03-01

Full Text Available Musa acuminata cultivar pisang ambon lumut is a native climacteric fruit from Indonesia. Climacteric fruit ripening process is triggered by the gaseous plant hormone ethylene. The rate limiting enzyme involved in ethylene biosynthesis is ACC synthase (ACS which is encoded by ACS gene family. The objective of this study is to identify MA-ACS gene family in M. acuminata cultivar pisang ambon lumut and to study the MA-ACS1 gene expression. The result showed that there were nine M. acuminata ACS gene family members called MA-ACS1–9. Two of them (MA-ACS1 and MA-ACS2 were assessed using reverse transcriptase PCR (RT-PCR for gene expression study and it was only MA-ACS1 correlated with fruit ripening. The MA-ACS1 gene fragment has been successfully isolated and characterized and it has three introns, four exons, and one stop codon. It also shows highest homology with MACS1 gene from M. acuminata cultivar Hsian Jien Chiao (GenBank accession number AF056164. Expression analysis of MA-ACS1 using quantitative PCR (qPCR showed that MA-ACS1 gene expression increased significantly in the third day, reached maximum at the fifth day, and then decreased in the seventh day after harvesting. The qPCR expression analysis result correlated with the result of physical analysis during fruit ripening.

Universality of ac conduction in disordered solids

DEFF Research Database (Denmark)

Dyre, Jeppe; Schrøder, Thomas

2000-01-01

The striking similarity of ac conduction in quite different disordered solids is discussed in terms of experimental results, modeling, and computer simulations. After giving an overview of experiment, a macroscopic and a microscopic model are reviewed. For both models the normalized ac conductivity...... as a function of a suitably scaled frequency becomes independent of details of the disorder in the extreme disorder limit, i.e., when the local randomly varying mobilities cover many orders of magnitude. The two universal ac conductivities are similar, but not identical; both are examples of unusual non......-power-law universalities. It is argued that ac universality reflects an underlying percolation determining dc as well as ac conductivity in the extreme disorder limit. Three analytical approximations to the universal ac conductivities are presented and compared to computer simulations. Finally, model predictions...

Survey reveals public open to ban on hand-held cell phone use and texting.

Science.gov (United States)

2013-01-01

A study performed by the Bureau of Transportation Statistics (BTS) reveals that the public is open to a ban on hand-held cell phone use while driving. The study is based on data from 2009s Omnibus Household Survey (OHS), which is administered by B...

Burkina Faso - Roads Baseline Survey

Data.gov (United States)

Millennium Challenge Corporation — NOTE !!!This survey data was not used for any independent evaluation reports!!! Impaq worked with the data collection firms NSCE-MCG-AC3E [the Group] to conduct...

Construction and characterisation of near-isogenic Plutella xylostella (Lepidoptera: Plutellidae) strains resistant to Cry1Ac toxin.

Science.gov (United States)

Zhu, Xun; Lei, Yanyuan; Yang, Yanjv; Baxter, Simon W; Li, Jianhong; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Guo, Zhaojiang; Fu, Wei; Zhang, Youjun

2015-02-01

Resistance to insecticidal Bacillus thuringiensis (Bt) toxins has arisen in multiple populations of the worldwide Brassica pest Plutella xylostella (L.). To help elucidate the mechanism of resistance to Bt Cry1Ac toxin in a population from Florida, two pairs of near-isogenic lines (NILs) were developed. NILs were generated using either backcross or recombinant inbred line methodologies and evaluated for near-isogenicity with inter-simple-sequence-repeat (ISSR) markers. Backcross line BC6F4 maintained a similar level of Cry1Ac resistance to parental strain DBM1Ac-R (>5000-fold) yet showed 98.24% genetic similarity to the susceptible parental strain DBM1Ac-S. Single-pair backcrosses between DBM1Ac-S and BC6F4 revealed that Cry1Ac resistance was controlled by one recessive autosomal locus. BC6F4 exhibited high levels of cross-resistance to Cry1Ab and Cry1Ah but not to Cry1Ca or Cry1Ie. Near-isogenic strains were constructed to provide a reliable biological system to investigate the mechanism of Cry1Ac resistance in P. xylostella. These data suggest that resistance to Cry1Ac, Cry1Ab and Cry1Ah is probably caused by the alteration of a common receptor not recognised by Cry1Ca or Cry1Ie. Understanding Bt toxin cross-resistance provides valuable information to consider when developing pest control strategies to delay resistance evolution. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.

AcMNPV

African Journals Online (AJOL)

USER

2010-08-16

Aug 16, 2010 ... biosynthesis pathway and plays an important role in insect growth and .... Construction and propagation of recombined AcMNPV. The recombined ... infected by virus increased with incubation time (Figure. 3). The growth of ...

Modeling and reliability analysis of three phase z-source AC-AC converter

Directory of Open Access Journals (Sweden)

Prasad Hanuman

2017-12-01

Full Text Available This paper presents the small signal modeling using the state space averaging technique and reliability analysis of a three-phase z-source ac-ac converter. By controlling the shoot-through duty ratio, it can operate in buck-boost mode and maintain desired output voltage during voltage sag and surge condition. It has faster dynamic response and higher efficiency as compared to the traditional voltage regulator. Small signal analysis derives different control transfer functions and this leads to design a suitable controller for a closed loop system during supply voltage variation. The closed loop system of the converter with a PID controller eliminates the transients in output voltage and provides steady state regulated output. The proposed model designed in the RT-LAB and executed in a field programming gate array (FPGA-based real-time digital simulator at a fixedtime step of 10 μs and a constant switching frequency of 10 kHz. The simulator was developed using very high speed integrated circuit hardware description language (VHDL, making it versatile and moveable. Hardware-in-the-loop (HIL simulation results are presented to justify the MATLAB simulation results during supply voltage variation of the three phase z-source ac-ac converter. The reliability analysis has been applied to the converter to find out the failure rate of its different components.

Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.; Andersen, Michael A.E.

2005-07-01

This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion will provide better efficiency and higher level of integration, leading to lower component count, volume and cost, but at the expense of a minor performance deterioration. (au)

Proportional-Integral-Resonant AC Current Controller

Directory of Open Access Journals (Sweden)

STOJIC, D.

2017-02-01

Full Text Available In this paper an improved stationary-frame AC current controller based on the proportional-integral-resonant control action (PIR is proposed. Namely, the novel two-parameter PIR controller is applied in the stationary-frame AC current control, accompanied by the corresponding parameter-tuning procedure. In this way, the proportional-resonant (PR controller, common in the stationary-frame AC current control, is extended by the integral (I action in order to enable the AC current DC component tracking, and, also, to enable the DC disturbance compensation, caused by the voltage source inverter (VSI nonidealities and by nonlinear loads. The proposed controller parameter-tuning procedure is based on the three-phase back-EMF-type load, which corresponds to a wide range of AC power converter applications, such as AC motor drives, uninterruptible power supplies, and active filters. While the PIR controllers commonly have three parameters, the novel controller has two. Also, the provided parameter-tuning procedure needs only one parameter to be tuned in relation to the load and power converter model parameters, since the second controller parameter is directly derived from the required controller bandwidth value. The dynamic performance of the proposed controller is verified by means of simulation and experimental runs.

Effects of AC Electric Field on Small Laminar Nonpremixed Flames

KAUST Repository

Xiong, Yuan

2015-04-01

baseline case, leading to the formation of toroidal vortices. Increased residence time and heat recirculation inside the vortex resulted in appreciable formation of PAHs and soot near the nozzle exit. Decreased residence time along the jet axis through flow acceleration by the vortex led to a reduction in the soot volume fraction in the downstream sooting zone. Electromagnetic force generated by AC was proposed as a viable mechanism for the formation of the toroidal vortex. By varying applied AC in a wide range of frequency and voltage, several insta- bility modes were observed, including flicking flames, partial pinch-off of flames, and spinning flames. High speed imaging together with Mie scattering techniques were combined to reveal the flame dynamics as well as the flow structure inside the flames. Original steady toroidal vortices triggered by AC were noted to exhibit axisymmetric axial instability in the flicking and partial pinch-off modes and non-axisymmetric azimuthal instability in the spinning mode. Electrical measurements were also conducted simultaneously to identify the voltage, current, and electrical power responses. Integrated power was noted to be sensitive to indicate subtle variation of flames properties and to the occurrence of axial instability. Under low frequency AC forcing with electrical conditions not generating toroidal vortices, responses of flames were further investigated. Several nonlinear flame responses, including frequency doubling and tripling phenomena, were identified. Spectral analysis revealed that such nonlinear responses were attributed to the combined effects of triggering buoyancy-induced oscillation of the flame as well as the Lorenz force generated by applying AC. Phase delay behaviors between the applied voltage and the heat release rate (or flame size) were also studied to explore the potential of applying AC in controlling flame instability. It was found that the phase delay had large variations for AC frequency smaller than

Facial cellulitis revealing choreo-acanthocytosis: A case report ...

African Journals Online (AJOL)

We report a 62 year-old-man with facial cellulitis revealing choreo-acanthocytosis (ChAc). He showed chorea that started 20 years ago. The orofacial dyskinisia with tongue and cheek biting resulted in facial cellulitis. The peripheral blood smear revealed acanthocytosis of 25%. The overall of chorea, orofacial dyskinetic ...

Low ac loss geometries in YBCO coated conductors

International Nuclear Information System (INIS)

Duckworth, R.C.; List, F.A.; Paranthaman, M.P.; Rupich, M.W.; Zhang, W.; Xie, Y.Y.; Selvamanickam, V.

2007-01-01

Reduction of ac losses in applied ac fields can be accomplished through either the creation of filaments and bridging in YBCO coated conductors or by an assembly of narrow width YBCO tapes. The ac losses for each of these geometries were measured at 77 K in perpendicular ac fields up to 100 mT. Despite physical isolation of the filaments, coupling losses were still present in the samples when compared to the expected hysteretic loss. In addition to filamentary conductors the assembly of stacked YBCO conductor provides an alternative method of ac loss reduction. When compared to a 4-mm wide YBCO coated conductor with a critical current of 60 A, the ac loss in a stack of 2-mm wide YBCO coated conductors with a similar total critical current was reduced. While the reduction in ac loss in a 2-mm wide stack coincided with the reduction in the engineering current density of the conductor, further reduction of ac loss was obtained through the splicing of the 2-mm wide tapes with low resistance solders

Low ac loss geometries in YBCO coated conductors

Energy Technology Data Exchange (ETDEWEB)

Duckworth, R.C. [Oak Ridge National Laboratory, One Bethel Valley Road, P.O. Box 2008, MS-6305, Oak Ridge, TN 37831-6305 (United States)], E-mail: duckworthrc@ornl.gov; List, F.A.; Paranthaman, M.P. [Oak Ridge National Laboratory, One Bethel Valley Road, P.O. Box 2008, MS-6305, Oak Ridge, TN 37831-6305 (United States); Rupich, M.W.; Zhang, W. [American Superconductor, Two Technology Drive, Westborough, MA 01581 (United States); Xie, Y.Y.; Selvamanickam, V. [SuperPower, 450 Duane Ave, Schenectady, NY 12304 (United States)

2007-10-01

Reduction of ac losses in applied ac fields can be accomplished through either the creation of filaments and bridging in YBCO coated conductors or by an assembly of narrow width YBCO tapes. The ac losses for each of these geometries were measured at 77 K in perpendicular ac fields up to 100 mT. Despite physical isolation of the filaments, coupling losses were still present in the samples when compared to the expected hysteretic loss. In addition to filamentary conductors the assembly of stacked YBCO conductor provides an alternative method of ac loss reduction. When compared to a 4-mm wide YBCO coated conductor with a critical current of 60 A, the ac loss in a stack of 2-mm wide YBCO coated conductors with a similar total critical current was reduced. While the reduction in ac loss in a 2-mm wide stack coincided with the reduction in the engineering current density of the conductor, further reduction of ac loss was obtained through the splicing of the 2-mm wide tapes with low resistance solders.

Analysis of genomic DNA of DcACS1, a 1-aminocyclopropane-1-carboxylate synthase gene, expressed in senescing petals of carnation (Dianthus caryophyllus) and its orthologous genes in D. superbus var. longicalycinus.

Science.gov (United States)

Harada, Taro; Murakoshi, Yuino; Torii, Yuka; Tanase, Koji; Onozaki, Takashi; Morita, Shigeto; Masumura, Takehiro; Satoh, Shigeru

2011-04-01

Carnation (Dianthus caryophyllus) flowers exhibit climacteric ethylene production followed by petal wilting, a senescence symptom. DcACS1, which encodes 1-aminocyclopropane-1-carboxylate synthase (ACS), is a gene involved in this phenomenon. We determined the genomic DNA structure of DcACS1 by genomic PCR. In the genome of 'Light Pink Barbara', we found two distinct nucleotide sequences: one corresponding to the gene previously shown as DcACS1, designated here as DcACS1a, and the other novel one designated as DcACS1b. It was revealed that both DcACS1a and DcACS1b have five exons and four introns. These two genes had almost identical nucleotide sequences in exons, but not in some introns and 3'-UTR. Analysis of transcript accumulation revealed that DcACS1b is expressed in senescing petals as well as DcACS1a. Genomic PCR analysis of 32 carnation cultivars showed that most cultivars have only DcACS1a and some have both DcACS1a and DcACS1b. Moreover, we found two DcACS1 orthologous genes with different nucleotide sequences from D. superbus var. longicalycinus, and designated them as DsuACS1a and DsuACS1b. Petals of D. superbus var. longicalycinus produced ethylene in response to exogenous ethylene, accompanying accumulation of DsuACS1 transcripts. These data suggest that climacteric ethylene production in flowers was genetically established before the cultivation of carnation.

AC conductivity and dielectric behavior of bulk Furfurylidenemalononitrile

Science.gov (United States)

El-Nahass, M. M.; Ali, H. A. M.

2012-06-01

AC conductivity and dielectric behavior for bulk Furfurylidenemalononitrile have been studied over a temperature range (293-333 K) and frequency range (50-5×106 Hz). The frequency dependence of ac conductivity, σac, has been investigated by the universal power law, σac(ω)=Aωs. The variation of the frequency exponent (s) with temperature was analyzed in terms of different conduction mechanisms, and it was found that the correlated barrier hopping (CBH) model is the predominant conduction mechanism. The temperature dependence of σac(ω) showed a linear increase with the increase in temperature at different frequencies. The ac activation energy was determined at different frequencies. Dielectric data were analyzed using complex permittivity and complex electric modulus for bulk Furfurylidenemalononitrile at various temperatures.

Assay Methods for ACS Activity and ACS Phosphorylation by MAP Kinases In Vitro and In Vivo.

Science.gov (United States)

Han, Xiaomin; Li, Guojing; Zhang, Shuqun

2017-01-01

Ethylene, a gaseous phytohormone, has profound effects on plant growth, development, and adaptation to the environment. Ethylene-regulated processes begin with the induction of ethylene biosynthesis. There are two key steps in ethylene biosynthesis. The first is the biosynthesis of 1-aminocyclopropane-1-carboxylic acid (ACC) from S-Adenosyl-Methionine (SAM), a common precursor in many metabolic pathways, which is catalyzed by ACC synthase (ACS). The second is the oxidative cleavage of ACC to form ethylene under the action of ACC oxidase (ACO). ACC biosynthesis is the committing and generally the rate-limiting step in ethylene biosynthesis. As a result, characterizing the cellular ACS activity and understanding its regulation are important. In this chapter, we detail the methods used to measure, (1) the enzymatic activity of both recombinant and native ACS proteins, and (2) the phosphorylation of ACS protein by mitogen-activated protein kinases (MAPKs) in vivo and in vitro.

The influences of microwave irradiation and polyol precursor pH on Cu/AC catalyst and its CO oxidation performance

Science.gov (United States)

Chuang, Kui-Hao; Shih, Kaimin; Wey, Ming-Yen

2012-10-01

This study evaluated the effects of microwave irradiation parameters and the pH of the polyol precursor on the morphological features and catalytic performances of Cu/activated carbon (AC) catalysts. Experimental results of carbon monoxide (CO) oxidation indicated that the highest catalytic activity is achieved when the Cu/AC catalyst is prepared with microwave irradiation at 700 W for 60 s. Scanning electron microscopy revealed the presence of beneficial small copper aciculae on the Cu/AC catalyst under such a microwave irradiation scheme. Further investigation of operational parameters found that the performance of Cu/AC catalysts is enhanced by adopting a pH = 12 polyol precursor solution. With the observation that small cube copper ( 16 nm) aggregates form when a pH = 12 polyol precursor solution is used, this study also demonstrated the importance of controlling the morphology of metal nanoparticles on Cu/AC catalysts when using the microwave-assisted polyol method.

The influences of microwave irradiation and polyol precursor pH on Cu/AC catalyst and its CO oxidation performance

International Nuclear Information System (INIS)

Chuang, Kui-Hao; Shih, Kaimin; Wey, Ming-Yen

2012-01-01

This study evaluated the effects of microwave irradiation parameters and the pH of the polyol precursor on the morphological features and catalytic performances of Cu/activated carbon (AC) catalysts. Experimental results of carbon monoxide (CO) oxidation indicated that the highest catalytic activity is achieved when the Cu/AC catalyst is prepared with microwave irradiation at 700 W for 60 s. Scanning electron microscopy revealed the presence of beneficial small copper aciculae on the Cu/AC catalyst under such a microwave irradiation scheme. Further investigation of operational parameters found that the performance of Cu/AC catalysts is enhanced by adopting a pH = 12 polyol precursor solution. With the observation that small cube copper (∼16 nm) aggregates form when a pH = 12 polyol precursor solution is used, this study also demonstrated the importance of controlling the morphology of metal nanoparticles on Cu/AC catalysts when using the microwave-assisted polyol method.

Demographics for US Census Tracts - 2012 (American Community Survey 2008-2012 Derived Summary Tables)

Data.gov (United States)

U.S. Environmental Protection Agency — This map service displays data derived from the 2008-2012 American Community Survey (ACS). Values derived from the ACS and used for this map service include: Total...

Demographics for US Census Tracts - 2010 (American Community Survey 2006-2010 Derived Summary Tables)

Data.gov (United States)

U.S. Environmental Protection Agency — This map service displays data derived from the 2006-2010 American Community Survey (ACS). Values derived from the ACS and used for this map service include: Total...

RNA interference suppression of mucin 5AC (MUC5AC reduces the adhesive and invasive capacity of human pancreatic cancer cells

Directory of Open Access Journals (Sweden)

Yamada Nobuya

2010-05-01

Full Text Available Abstract Background MUC5AC is a secretory mucin normally expressed in the surface muconous cells of stomach and bronchial tract. It has been known that MUC5AC de novo expression occurred in the invasive ductal carcinoma and pancreatic intraepithelial neoplasm with no detectable expression in normal pancreas, however, its function remains uncertain. Here, we report the impact of MUC5AC on the adhesive and invasive ability of pancreatic cancer cells. Methods We used two MUC5AC expressing cell lines derived from human pancreatic cancer, SW1990 and BxPC3. Small-interfering (si RNA directed against MUC5AC were used to assess the effects of MUC5AC on invasion and adhesion of pancreas cancer cells in vitro and in vivo. We compared parental cells (SW1990 and BxPC3 with MUC5AC suppressed cells by si RNA (si-SW1990 and si-BxPC3. Results MUC5AC was found to express in more than 80% of pancreatic ductal carcinoma specimens. Next we observed that both of si-SW1990 and si-BxPC3 showed significantly lower adhesion and invasion to extracellular matrix components compared with parental cell lines. Expression of genes associated with adhesion and invasion including several integerins, matrix metalloproteinase (MMP -3 and vascular endothelial growth factor (VEGF were down-regulated in both MUC5AC suppressed cells. Furthermore, production of VEGF and phosphorylation of VEGFR-1 were significantly reduced by MUC5AC down regulation. Both of si-SW1990 and si-BxPC3 attenuated activation of Erk1/2. In vivo, si-SW1990 did not establish subcutaneous tumor in nude mice. Conclusions Knockdown of MUC5AC reduced the ability of pancreatic cancer cells to adhesion and invasion, suggesting that MUC5AC might contribute to the invasive motility of pancreatic cancer cells by enhancing the expression of integrins, MMP-3, VEGF and activating Erk pathway.

Characterization of tetraaza-AC8, a surfactant with cation complexing potential

International Nuclear Information System (INIS)

Arleth, Lise

1995-01-01

will thereby be given. The second chapter contains descriptions of the fundamental physical chemical measurements made in order to characterize the molecule in aqueous solutions. In order to decide whether respectively CsF, CuF_2 and RhCl_3 is complexed by the Tetraaza-AC8 molecule, pH and UV/visible light spectroscopy measurements are performed. Density measurements of the molecule are made and will show to be applicable later, for the interpretation of the small-angle scattering spectra. Finally surface tension measurements are performed in order to prove that a micellization takes place and to determine the areas per head-group of the micelles, which will also show to be applicable later, for the interpretation of the small-angle scattering data. The third and fourth chapter deal with what we regard as the core of the project, namely the small-angle scattering analysis of dilute solutions of Tetraaza-AC8 with respectively CsF, CuF_2 and RhCI_3. Chapter 3 gives a short survey of the fundamental theory of small-angle scattering, thereby descriptions of the applied SAXS and SANS facilities are given. At the end of the chapter the raw-data obtained are presented and discussed. Chapter 4 deals with the analysis of the obtained scattering data. The principles of the two applied methods of analysis are explained. At the end of the chapter the obtained results are presented and discussed. During the project several different experimental methods and techniques have been applied. It should, however, be emphasized that since the project is of experimental nature, only brief surveys of the theory, methods and models applied will be given. More detailed descriptions can in most cases be found in the fundamental literature

Hopping models and ac universality

DEFF Research Database (Denmark)

Dyre, Jeppe; Schrøder, Thomas

2002-01-01

Some general relations for hopping models are established. We proceed to discuss the universality of the ac conductivity which arises in the extreme disorder limit of the random barrier model. It is shown that the relevant dimension entering into the diffusion cluster approximation (DCA) is the h......Some general relations for hopping models are established. We proceed to discuss the universality of the ac conductivity which arises in the extreme disorder limit of the random barrier model. It is shown that the relevant dimension entering into the diffusion cluster approximation (DCA......) is the harmonic (fracton) dimension of the diffusion cluster. The temperature scaling of the dimensionless frequency entering into the DCA is discussed. Finally, some open problems regarding ac universality are listed....

Achievement report for fiscal 1999 on New Sunshine Program. Frontier research and development of basic superconductive AC power generation equipment; 1999 nendo koryu chodendo denryoku kiki kiban sendo kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

As part of the New Sunshine Program of the Agency of Industrial Science and Technology, a 2-year survey and research is conducted beginning in 1998 on the effect of the introduction of superconductive power equipment for the facilitation of the progress of research and development of basic power equipment which utilizes AC (alternating current) superconductivity. Frontier research and development has been started of basic AC superconductive power equipment for clarifying the tasks to solve in the development effort and for preparing an efficient research and development plan. This fiscal year's endeavor covers the survey of the effect of the introduction of superconductive power equipment in addition to the preparation of a basic plan for the research and development of basic AC superconductive power equipment for fiscal 2000 and afterward, continued survey of research and development trends in and outside Japan for the review of the result achieved in the preceding fiscal year, development of AC equipment element technologies utilizing conduit type semiconductors as a basic study for the embodiment of AC superconductive equipment, and a study for elucidating the mechanism of resistance generated in a superconductive current limiter. Furthermore, papers on the superconduction technology released so far are investigated, and technology development trends and efficient research techniques are put together into a technological information database. (NEDO)

Achievement report for fiscal 1999 on New Sunshine Program. Frontier research and development of basic superconductive AC power generation equipment; 1999 nendo koryu chodendo denryoku kiki kiban sendo kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

As part of the New Sunshine Program of the Agency of Industrial Science and Technology, a 2-year survey and research is conducted beginning in 1998 on the effect of the introduction of superconductive power equipment for the facilitation of the progress of research and development of basic power equipment which utilizes AC (alternating current) superconductivity. Frontier research and development has been started of basic AC superconductive power equipment for clarifying the tasks to solve in the development effort and for preparing an efficient research and development plan. This fiscal year's endeavor covers the survey of the effect of the introduction of superconductive power equipment in addition to the preparation of a basic plan for the research and development of basic AC superconductive power equipment for fiscal 2000 and afterward, continued survey of research and development trends in and outside Japan for the review of the result achieved in the preceding fiscal year, development of AC equipment element technologies utilizing conduit type semiconductors as a basic study for the embodiment of AC superconductive equipment, and a study for elucidating the mechanism of resistance generated in a superconductive current limiter. Furthermore, papers on the superconduction technology released so far are investigated, and technology development trends and efficient research techniques are put together into a technological information database. (NEDO)

Transport AC losses in YBCO coated conductors

Energy Technology Data Exchange (ETDEWEB)

Majoros, M [Ohio State University, Columbus, OH 43210 (United States); Ye, L [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Velichko, A V [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Coombs, T A [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Sumption, M D [Ohio State University, Columbus, OH 43210 (United States); Collings, E W [Ohio State University, Columbus, OH 43210 (United States)

2007-09-15

Transport AC loss measurements have been made on YBCO-coated conductors prepared on two different substrate templates-RABiTS (rolling-assisted biaxially textured substrate) and IBAD (ion-beam-assisted deposition). RABiTS samples show higher losses compared with the theoretical values obtained from the critical state model, with constant critical current density, at currents lower than the critical current. An origin of this extra AC loss was demonstrated experimentally by comparison of the AC loss of two samples with different I-V curves. Despite a difference in I-V curves and in the critical currents, their measured losses, as well as the normalized losses, were practically the same. However, the functional dependence of the losses was affected by the ferromagnetic substrate. An influence of the presence of a ferromagnetic substrate on transport AC losses in YBCO film was calculated numerically by the finite element method. The presence of a ferromagnetic substrate increases transport AC losses in YBCO films depending on its relative magnetic permeability. The two loss contributions-transport AC loss in YBCO films and ferromagnetic loss in the substrate-cannot be considered as mutually independent.

Expression Study of LeGAPDH, LeACO1, LeACS1A, and LeACS2 in Tomato Fruit (Solanum lycopersicum

Directory of Open Access Journals (Sweden)

Pijar Riza Anugerah

2015-10-01

Full Text Available Tomato is a climacteric fruit, which is characterized by ripening-related increase of respiration and elevated ethylene synthesis. Ethylene is the key hormone in ripening process of climacteric fruits. The objective of this research is to study the expression of three ethylene synthesis genes: LeACO1, LeACS1A, LeACS2, and a housekeeping gene LeGAPDH in ripening tomato fruit. Specific primers have been designed to amplify complementary DNA fragment of LeGAPDH (143 bp, LeACO1 (240 bp, LeACS1A (169 bp, and LeACS2 (148 bp using polymerase chain reaction. Nucleotide BLAST results of the complementary DNA fragments show high similarity with LeGAPDH (NM_001247874.1, LeACO1 (NM_001247095.1, LeACS1A (NM_001246993.1, LeACS2 (NM_001247249.1, respectively. Expression study showed that LeACO1, LeACS1A, LeACS2, and LeGAPDH genes were expressed in ripening tomato fruit. Isolation methods, reference sequences, and primers used in this study can be used in future experiments to study expression of genes responsible for ethylene synthesis using quantitative polymerase chain reaction and to design better strategy for controlling fruit ripening in agroindustry.

Repeat surveys of spawning cisco (Coregonus artedi) in western Lake Superior: timing, distribution and composition of spawning stocks

Science.gov (United States)

Yule, Daniel L.; Schreiner, Donald R.; Addison, Peter A.; Seider, Michael J.; Evrard, Lori M.; Geving, Steven A.; Quinlan, Henry R.

2012-01-01

Acoustic (AC) and midwater trawl (MT) surveys of spawning cisco (Coregonus artedi) in Lake Superior have been combined with commercial yield to estimate exploitation. To time surveys properly, it is important to understand when adults typically arrive at spawning grounds and how numbers change as the spawning season progresses. We conducted repeat autumn surveys during nighttime hours at coastal sites where commercial roe fisheries occur. Spawner densities increased significantly from October to mid-November, but differences measured at sites sampled from mid- to late-November were comparatively small. Spawners occupied the upper 20–30 m of the water column during mid-November before utilizing a wider range of depths by late-November. We compared repeat AC densities to temporal trends of catch-per-unit-effort (CPUE) in suspended commercial gillnets and found good agreement within sites. Because different gillnet mesh sizes were used in each roe fishery. CPUE and AC density were poorly correlated among sites. We recommend that future surveys be conducted between mid- and late-November, and that MT gear be used to measure cisco densities in the uppermost 10 m of the water column where AC estimates may be conservative. Given the short temporal window for assessing spawner density, we believe both AC-MT and gillnet surveys will be needed to ensure that harvest of different stocks is kept at a sustainable level.

Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

International Nuclear Information System (INIS)

Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua

2015-01-01

Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6 A -4-hydroxyethyl-1,2,3-triazolyl-6 C -3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study

Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

Energy Technology Data Exchange (ETDEWEB)

Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua, E-mail: whtang@mail.njust.edu.cn

2015-04-08

Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6{sup A}-4-hydroxyethyl-1,2,3-triazolyl-6{sup C}-3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study.

Dicty_cDB: FC-AC21 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available FC (Link to library) FC-AC21 (Link to dictyBase) - - - Contig-U15104-1 FC-AC21E (Li...nk to Original site) - - - - - - FC-AC21E 527 Show FC-AC21 Library FC (Link to library) Clone ID FC-AC21 (Link to dict...yBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U15104-1 Original site URL http://dict...ce KDSLDVIIFPEMVKLVGLTPNTMEKVLTYFQDNDTIDLSTFPMEIQVEQLSGKYIFICTH KQKDQRCGYCGPILVDQLRDQIKERSLEKEIQVFGTSHVGGHKY... Frames) Frame A: KDSLDVIIFPEMVKLVGLTPNTMEKVLTYFQDNDTIDLSTFPMEIQVEQLSGKYIFICTH KQ

Distribution and Metabolism of Bt-Cry1Ac Toxin in Tissues and Organs of the Cotton Bollworm, Helicoverpa armigera

Directory of Open Access Journals (Sweden)

Zhuoya Zhao

2016-07-01

Full Text Available Crystal (Cry proteins derived from Bacillus thuringiensis (Bt have been widely used in transgenic crops due to their toxicity against insect pests. However, the distribution and metabolism of these toxins in insect tissues and organs have remained obscure because the target insects do not ingest much toxin. In this study, several Cry1Ac-resistant strains of Helicoverpa armigera, fed artificial diets containing high doses of Cry1Ac toxin, were used to investigate the distribution and metabolism of Cry1Ac in their bodies. Cry1Ac was only detected in larvae, not in pupae or adults. Also, Cry1Ac passed through the midgut into other tissues, such as the hemolymph and fat body, but did not reach the larval integument. Metabolic tests revealed that Cry1Ac degraded most rapidly in the fat body, followed by the hemolymph, peritrophic membrane and its contents. The toxin was metabolized slowly in the midgut, but was degraded in all locations within 48 h. These findings will improve understanding of the functional mechanism of Bt toxins in target insects and the biotransfer and the bioaccumulation of Bt toxins in arthropod food webs in the Bt crop ecosystem.

THERMIONIC AC GENERATION

Science.gov (United States)

is shown that the maximum ac efficiency is equal to approximately 70% of the corresponding dc value. An illustrative example, including a proposed design for a rather unconventional transformer, is appended. (Author)

21 CFR 880.6320 - AC-powered medical examination light.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered medical examination light. 880.6320... Miscellaneous Devices § 880.6320 AC-powered medical examination light. (a) Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body...

Ac-dc converter firing error detection

International Nuclear Information System (INIS)

Gould, O.L.

1996-01-01

Each of the twelve Booster Main Magnet Power Supply modules consist of two three-phase, full-wave rectifier bridges in series to provide a 560 VDC maximum output. The harmonic contents of the twelve-pulse ac-dc converter output are multiples of the 60 Hz ac power input, with a predominant 720 Hz signal greater than 14 dB in magnitude above the closest harmonic components at maximum output. The 720 Hz harmonic is typically greater than 20 dB below the 500 VDC output signal under normal operation. Extracting specific harmonics from the rectifier output signal of a 6, 12, or 24 pulse ac-dc converter allows the detection of SCR firing angle errors or complete misfires. A bandpass filter provides the input signal to a frequency-to-voltage converter. Comparing the output of the frequency-to-voltage converter to a reference voltage level provides an indication of the magnitude of the harmonics in the ac-dc converter output signal

[Special Issue on SEA Demographics] Response - Language Policy: Using the American Community Survey to Investigate Bilingualism and Biliteracy among Immigrant Communities

Directory of Open Access Journals (Sweden)

Gerda de Klerk

2008-01-01

Full Text Available This article is a response to Mark Pfeifer’s Cambodian, Hmong, Lao and Vietnamese Americans in the 2005 American Community Survey and elaborates on the utility of the American Community Survey (ACS for studying immigrant groups in the United States of America, and also compares the ACS to the U.S. Census. Neither the Census nor ACS questionnaire is structured to capture the language and literacy skills of immigrant communities in as far as these surveys only collect information about respondents’ oral language abilities, with a focus on English fluency. Direct, self-reported, and surrogate measures of literacy are discussed, with a proposal to use education level as surrogate for literacy. Using the Vietnamese subpopulation in the ACS, examples are presented of ways to construct composite variables from the ACS raw microdata, to measure respondents’ bilingualism and biliteracy. When such new variables are used in analysis of immigrant communities, a more complex multilingual picture emerges than is presented normally in Census and ACS data products available to the public.

Effect of Low-Frequency AC Magnetic Susceptibility and Magnetic Properties of CoFeB/MgO/CoFeB Magnetic Tunnel Junctions

Directory of Open Access Journals (Sweden)

Yuan-Tsung Chen

2014-01-01

Full Text Available In this investigation, the low-frequency alternate-current (AC magnetic susceptibility (χac and hysteresis loop of various MgO thickness in CoFeB/MgO/CoFeB magnetic tunneling junction (MTJ determined coercivity (Hc and magnetization (Ms and correlated that with χac maxima. The multilayer films were sputtered onto glass substrates and the thickness of intermediate barrier MgO layer was varied from 6 to 15 Å. An experiment was also performed to examine the variation of the highest χac and maximum phase angle (θmax at the optimal resonance frequency (fres, at which the spin sensitivity is maximal. The results reveal that χac falls as the frequency increases due to the relationship between magnetization and thickness of the barrier layer. The maximum χac is at 10 Hz that is related to the maximal spin sensitivity and that this corresponds to a MgO layer of 11 Å. This result also suggests that the spin sensitivity is related to both highest χac and maximum phase angle. The corresponding maximum of χac is related to high exchange coupling. High coercivity and saturation magnetization contribute to high exchange-coupling χac strength.

Nature of Dielectric Properties, Electric Modulus and AC Electrical Conductivity of Nanocrystalline ZnIn2Se4 Thin Films

Science.gov (United States)

El-Nahass, M. M.; Attia, A. A.; Ali, H. A. M.; Salem, G. F.; Ismail, M. I.

2018-02-01

The structural characteristics of thermally deposited ZnIn2Se4 thin films were indexed utilizing x-ray diffraction as well as scanning electron microscopy techniques. Dielectric properties, electric modulus and AC electrical conductivity of ZnIn2Se4 thin films were examined in the frequency range from 42 Hz to 106 Hz. The capacitance, conductance and impedance were measured at different temperatures. The dielectric constant and dielectric loss decrease with an increase in frequency. The maximum barrier height was determined from the analysis of the dielectric loss depending on the Giuntini model. The real part of the electric modulus revealed a constant maximum value at higher frequencies and the imaginary part of the electric modulus was characterized by the appearance of dielectric relaxation peaks. The AC electrical conductivity obeyed the Jonscher universal power law. Correlated barrier hopping model was the appropriate mechanism for AC conduction in ZnIn2Se4 thin films. Estimation of the density of states at the Fermi level and activation energy, for AC conduction, was carried out based on the temperature dependence of AC electrical conductivity.

Transcranial Alternating Current Stimulation (tACS Mechanisms and Protocols

Directory of Open Access Journals (Sweden)

Amir V. Tavakoli

2017-09-01

Full Text Available Perception, cognition and consciousness can be modulated as a function of oscillating neural activity, while ongoing neuronal dynamics are influenced by synaptic activity and membrane potential. Consequently, transcranial alternating current stimulation (tACS may be used for neurological intervention. The advantageous features of tACS include the biphasic and sinusoidal tACS currents, the ability to entrain large neuronal populations, and subtle control over somatic effects. Through neuromodulation of phasic, neural activity, tACS is a powerful tool to investigate the neural correlates of cognition. The rapid development in this area requires clarity about best practices. Here we briefly introduce tACS and review the most compelling findings in the literature to provide a starting point for using tACS. We suggest that tACS protocols be based on functional brain mechanisms and appropriate control experiments, including active sham and condition blinding.

Differential lysine acetylation profiles of Erwinia amylovora strains revealed by proteomics

Science.gov (United States)

Wu, Xia; Vellaichamy, Adaikkalam; Wang, Dongping; Zamdborg, Leonid; Kelleher, Neil L.; Huber, Steven C.; Zhao, Youfu

2015-01-01

Protein lysine acetylation (LysAc) has recently been demonstrated to be widespread in E. coli and Salmonella, and to broadly regulate bacterial physiology and metabolism. However, LysAc in plant pathogenic bacteria is largely unknown. Here we first report the lysine acetylome of Erwinia amylovora, an enterobacterium causing serious fire blight disease of apples and pears. Immunoblots using generic anti-lysine acetylation antibodies demonstrated that growth conditions strongly affected the LysAc profiles in E. amylovora. Differential LysAc profiles were also observed for two E. amylovora strains, known to have differential virulence in plants, indicating translational modification of proteins may be important in determining virulence of bacterial strains. Proteomic analysis of LysAc in two E. amylovora strains identified 141 LysAc sites in 96 proteins that function in a wide range of biological pathways. Consistent with previous reports, 44% of the proteins are involved in metabolic processes, including central metabolism, lipopolysaccharide, nucleotide and amino acid metabolism. Interestingly, for the first time, several proteins involved in E. amylovora virulence, including exopolysaccharide amylovoran biosynthesis- and type III secretion-associated proteins, were found to be lysine acetylated, suggesting that LysAc may play a major role in bacterial virulence. Comparative analysis of LysAc sites in E. amylovora and E. coli further revealed the sequence and structural commonality for LysAc in the two organisms. Collectively, these results reinforce the notion that LysAc of proteins is widespread in bacterial metabolism and virulence. PMID:23234799

Three-Level AC-DC-AC Z-Source Converter Using Reduced Passive Component Count

DEFF Research Database (Denmark)

Loh, Poh Chiang; Gao, Feng; Tan, Pee-Chin

2009-01-01

This paper presents a three-level ac-dc-ac Z-source converter with output voltage buck-boost capability. The converter is implemented by connecting a low-cost front-end diode rectifier to a neutral-point-clamped inverter through a single X-shaped LC impedance network. The inverter is controlled...... to switch with a three-level output voltage, where the middle neutral potential is uniquely tapped from the star-point of a wye-connected capacitive filter placed before the front-end diode rectifier for input current filtering. Through careful control, the resulting converter can produce the correct volt...

Characterisation of AC1: a naturally decaffeinated coffee

Directory of Open Access Journals (Sweden)

Luciana Benjamim Benatti

2012-01-01

Full Text Available We compared the biochemical characteristics of the beans of a naturally decaffeinated Arabica coffee (AC1 discovered in 2004 with those of the widely grown Brazilian Arabica cultivar "Mundo Novo" (MN. Although we observed differences during fruit development, the contents of amino acids, organic acids, chlorogenic acids, soluble sugars and trigonelline were similar in the ripe fruits of AC1 and MN. AC1 beans accumulated theobromine, and caffeine was almost entirely absent. Tests on the supply of [2-14C] adenine and enzymatic analysis of theobromine synthase and caffeine synthase in the endosperm of AC1 confirmed that, as in the leaves, caffeine synthesis is blocked during the methylation of theobromine to caffeine. The quality of the final coffee beverage obtained from AC1 was similar to that of MN.

Out-of-equilibrium fluctuation-dissipation relations verified by the electrical and thermoelectrical AC-conductances in a quantum dot

Energy Technology Data Exchange (ETDEWEB)

Crepieux, Adeline [Aix Marseille Univ., Universite de Toulon, CNRS, CPT, Marseille (France)

2017-09-15

The electrical and heat currents flowing through a quantum dot are calculated in the presence of a time-modulated gate voltage with the help of the out-of-equilibrium Green function technique. From the first harmonics of the currents, we extract the electrical and thermoelectrical trans-admittances and ac-conductances. Next, by a careful comparison of the ac-conductances with the finite-frequency electrical and mixed electrical-heat noises, we establish the fluctuation-dissipation relations linking these quantities, which are thus generalized out-of-equilibrium for a quantum system. It is shown that the electrical ac-conductance associated to the displacement current is directly linked to the electrical noise summed over reservoirs, whereas the relation between the thermoelectrical ac-conductance and the mixed noise contains an additional term proportional to the energy step that the electrons must overcome when traveling through the junction. A numerical study reveals however that a fluctuation-dissipation relation involving a single reservoir applies for both electrical and thermoelectrical ac-conductances when the frequency dominates over the other characteristic energies. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A multi-channel AC power supply controller

International Nuclear Information System (INIS)

Su Hong; Li Xiaogang; Ma Xiaoli; Zhou Bo; Yin Weiwei

2003-01-01

A multi-channel ac power supply controller developed recently by authors is introduced briefly in this paper. This controller is a computer controlled multi-electronic-switch device. This controller was developed for the automatic control and monitoring system of a 220 V ac power supply system, it is a key front-end device of the automatic control and monitoring system. There is an electronic switch in each channel, the rated load power is ≤1 kW/each channel. Another function is to sample the 220 V ac output voltage so that computer can monitor the operation state of each electronic switch. Through these switches, the 220 V ac power supply is applied to some device or apparatus that need to be powered by 220 V ac power supply. In the design, a solid-state relay was employed as an electronic switch. This controller can be connected in cascade mode. There are 8 boxes at most can be connected in cascade mode. The length of control word is 8 bit, which contains addressing information and electronic switch state setting information. The sampling output of the controller is multiplexed. It is only one bit that indicates the operating state of an electronic switch. This controller has been used in an automatic control and monitoring system for 220 V ac power supply system

Bioinformatics and Astrophysics Cluster (BinAc)

Science.gov (United States)

Krüger, Jens; Lutz, Volker; Bartusch, Felix; Dilling, Werner; Gorska, Anna; Schäfer, Christoph; Walter, Thomas

2017-09-01

BinAC provides central high performance computing capacities for bioinformaticians and astrophysicists from the state of Baden-Württemberg. The bwForCluster BinAC is part of the implementation concept for scientific computing for the universities in Baden-Württemberg. Community specific support is offered through the bwHPC-C5 project.

Preliminary Therapy Evaluation of 225Ac-DOTA-c(RGDyK) Demonstrates that Cerenkov Radiation Derived from 225Ac Daughter Decay Can Be Detected by Optical Imaging for In Vivo Tumor Visualization

Science.gov (United States)

Pandya, Darpan N.; Hantgan, Roy; Budzevich, Mikalai M.; Kock, Nancy D.; Morse, David L.; Batista, Izadora; Mintz, Akiva; Li, King C.; Wadas, Thaddeus J.

2016-01-01

The theranostic potential of 225Ac-based radiopharmaceuticals continues to increase as researchers seek innovative ways to harness the nuclear decay of this radioisotope for therapeutic and imaging applications. This communication describes the evaluation of 225Ac-DOTA-c(RGDyK) in both biodistribution and Cerenkov luminescence imaging (CLI) studies. Initially, La-DOTA-c(RGDyK) was prepared as a non-radioactive surrogate to evaluate methodologies that would contribute to an optimized radiochemical synthetic strategy and estimate the radioactive conjugate's affinity for αvβ3, using surface plasmon resonance spectroscopy. Surface plasmon resonance spectroscopy studies revealed the IC50 and Ki of La-DOTA-c(RGDyK) to be 33 ± 13 nM and 26 ± 11 nM, respectively, and suggest that the complexation of the La3+ ion to the conjugate did not significantly alter integrin binding. Furthermore, use of this surrogate allowed optimization of radiochemical synthesis strategies to prepare 225Ac-DOTA-c(RGDyK) with high radiochemical purity and specific activity similar to other 225Ac-based radiopharmaceuticals. This radiopharmaceutical was highly stable in vitro. In vivo biodistribution studies confirmed the radiotracer's ability to target αvβ3 integrin with specificity; specificity was detected in tumor-bearing animals using Cerenkov luminescence imaging. Furthermore, tumor growth control was achieved using non-toxic doses of the radiopharmaceutical in U87mg tumor-bearing nude mice. To our knowledge, this is the first report to describe the CLI of αvβ3+ tumors in live animals using the daughter products derived from 225Ac decay in situ. This concept holds promise to further enhance development of targeted alpha particle therapy. PMID:27022417

Ac, La, and Ce radioimpurities in {sup 225}Ac produced in 40-200 MeV proton irradiations of thorium

Energy Technology Data Exchange (ETDEWEB)

Engle, Jonathan W.; Ballard, Beau D. [Los Alamos National Laboratory, NM (United States); Weidner, John W. [Air Force Institute of Technology, Wright Patterson Air Force Base, OH (United States); and others

2014-10-01

Accelerator production of {sup 225}Ac addresses the global supply deficiency currently inhibiting clinical trials from establishing {sup 225}Ac's therapeutic utility, provided that the accelerator product is of sufficient radionuclidic purity for patient use. Two proton activation experiments utilizing the stacked foil technique between 40 and 200 MeV were employed to study the likely co-formation of radionuclides expected to be especially challenging to separate from {sup 225}Ac. Foils were assayed by nondestructive γ-spectroscopy and by α-spectroscopy of chemically processed target material. Nuclear formation cross sections for the radionuclides {sup 226}Ac and {sup 227}Ac as well as lower lanthanide radioisotopes {sup 139}Ce, {sup 141}Ce, {sup 143}Ce, and {sup 140}La whose elemental ionic radii closely match that of actinium were measured and are reported. The predictions of the latest MCNP6 event generators are compared with measured data, as they permit estimation of the formation rates of other radionuclides whose decay emissions are not clearly discerned in the complex spectra collected from {sup 232}Th(p,x) fission product mixtures. (orig.)

The ZTF Bright Transient Survey

Science.gov (United States)

Fremling, C.; Sharma, Y.; Kulkarni, S. R.; Miller, A. A.; Taggart, K.; Perley, D. A.; Gooba, A.

2018-06-01

As a supplement to the Zwicky Transient Facility (ZTF; ATel #11266) public alerts (ATel #11685) we plan to report (following ATel #11615) bright probable supernovae identified in the raw alert stream from the ZTF Northern Sky Survey ("Celestial Cinematography"; see Bellm & Kulkarni, 2017, Nature Astronomy 1, 71) to the Transient Name Server (https://wis-tns.weizmann.ac.il) on a daily basis; the ZTF Bright Transient Survey (BTS; see Kulkarni et al., 2018; arXiv:1710.04223).

Urine storage under refrigeration preserves the sample in chemical, cellularity and bacteriuria analysis of ACS

Directory of Open Access Journals (Sweden)

Karen Cristina Barcellos Ribeiro

2013-12-01

Full Text Available INTRODUCTION: The analysis of urine abnormal constituents and sediment (ACS comprises tests of great diagnostic and prognostic value in clinical practice. When the analysis of ACS cannot be performed within two hours after collection, the sample must be preserved in order to avoid pre-analytical interferences. Refrigeration is the most applied technique due to its cost effectiveness. Moreover, it presents fewer inconveniences when compared to chemical preservation. However, changes in ACS may also occur in samples under refrigeration. OBJECTIVE: To analyze the influence of refrigeration at 2 to 8ºC on the storage of urine samples within 24 hours. MATERIAL AND METHOD: A total of 80 urine samples were selected from patients admitted at Universidade Federal de Juiz de Fora (UFJF university hospital, which were tested for ACS at room temperature and stored under refrigeration for 6, 12 and 24 hours. RESULTS: The results showed that refrigeration proved to be effective when compared to samples kept at room temperature, inasmuch as the physical, chemical, microbial and cellularity features were preserved. Nevertheless, crystalluria was present after a 6- hour storage period. CONCLUSION: The tests revealed that cooling preserved cellularity and chemical characteristics of urine samples for up to 12 hours. Nonetheless, the precipitation of crystals was evident in this storage method. Thus, the possible consequences of storing urine samples for ACS test under these conditions should be included in the analysis report.

HST/ACS DIRECT AGES OF THE DWARF ELLIPTICAL GALAXIES NGC 147 AND NGC 185

Energy Technology Data Exchange (ETDEWEB)

Geha, M. [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Weisz, D. [Astronomy Department, Box 351580, University of Washington, Seattle, WA 98195 (United States); Grocholski, A. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Dolphin, A. [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Marel, R. P. van der [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Guhathakurta, P., E-mail: marla.geha@yale.edu [UCO/Lick Observatory, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)

2015-10-01

We present the deepest optical photometry for any dwarf elliptical (dE) galaxy based on Hubble Space Telescope Advanced Camera for Surveys (ACS) observations of the Local Group dE galaxies NGC 147 and NGC 185. Our F606W and F814W color–magnitude diagrams are the first to reach below the oldest main sequence turnoff in a dE galaxy, allowing us to determine full star formation histories in these systems. The ACS fields are located roughly ∼1.5 effective radii from the galaxy center to avoid photometric crowding. While both ACS fields show unambiguous evidence for old and intermediate age stars, the mean age of NGC 147 is ∼4–5 Gyr younger as compared to NGC 185. In NGC 147, only 40% of stars were in place 12.5 Gyr ago (z ∼ 5), with the bulk of the remaining stellar population forming between 5 to 7 Gyr. In contrast, 70% of stars were formed in NGC 185 prior to 12.5 Gyr ago with the majority of the remaining population forming between 8 to 10 Gyr ago. Star formation has ceased in both ACS fields for at least 3 Gyr. Previous observations in the central regions of NGC 185 show evidence for star formation as recent as 100 Myr ago, and a strong metallicity gradient with radius. This implies a lack of radial mixing between the center of NGC 185 and our ACS field. The lack of radial gradients in NGC 147 suggests that our inferred SFHs are more representative of its global history. We interpret the inferred differences in star formation histories to imply an earlier infall time into the M31 environment for NGC 185 as compared to NGC 147.

Catalytic performance and durability of Ni/AC for HI decomposition in sulfur–iodine thermochemical cycle for hydrogen production

International Nuclear Information System (INIS)

Fu, Guangshi; He, Yong; Zhang, Yanwei; Zhu, Yanqun; Wang, Zhihua; Cen, Kefa

2016-01-01

Highlights: • The relation between Ni content and Ni particle dispersion were disclosed. • The effect of Ni content on the catalytic activity of Ni/AC catalyst was revealed. • The optimal content of Ni for Ni/AC catalysts in HI decomposition was found. - Abstract: This work reports the Ni content effect on the Ni/AC catalytic performance in the HI decomposition reaction of the sulfur–iodine (SI) thermochemical cycle for hydrogen production and the Ni/AC catalyst durability in a long-term test. Accordingly, five catalysts with the Ni content ranging from 5% to 15% were prepared by an incipient-wetness impregnation method. The activity of all catalysts was examined under the temperature range of 573–773 K. The catalytic performance evaluation suggests that Ni content plays a significant role in the Ni dispersion, Ni particle size, and eventually the catalytic activity in HI decomposition. 12% is the optimal Ni content for Ni/AC catalysts in HI decomposition which is balanced between poor dispersion of Ni particles and increasing active center. The results of 24 h durability test, which incorporated with BET and TEM investigations of the 12%Ni/AC catalyst before and after the reaction, indicate that establishing a better Ni particle dispersion pattern and improving the stability of Ni particles on the support should be considered in the future.

THE ACS NEARBY GALAXY SURVEY TREASURY. IX. CONSTRAINING ASYMPTOTIC GIANT BRANCH EVOLUTION WITH OLD METAL-POOR GALAXIES

International Nuclear Information System (INIS)

Girardi, Leo; Williams, Benjamin F.; Gilbert, Karoline M.; Rosenfield, Philip; Dalcanton, Julianne J.; Marigo, Paola; Boyer, Martha L.; Dolphin, Andrew; Weisz, Daniel R.; Skillman, Evan; Melbourne, Jason; Olsen, Knut A. G.; Seth, Anil C.

2010-01-01

In an attempt to constrain evolutionary models of the asymptotic giant branch (AGB) phase at the limit of low masses and low metallicities, we have examined the luminosity functions and number ratios between AGB and red giant branch (RGB) stars from a sample of resolved galaxies from the ACS Nearby Galaxy Survey Treasury. This database provides Hubble Space Telescope optical photometry together with maps of completeness, photometric errors, and star formation histories for dozens of galaxies within 4 Mpc. We select 12 galaxies characterized by predominantly metal-poor populations as indicated by a very steep and blue RGB, and which do not present any indication of recent star formation in their color-magnitude diagrams. Thousands of AGB stars brighter than the tip of the RGB (TRGB) are present in the sample (between 60 and 400 per galaxy), hence, the Poisson noise has little impact in our measurements of the AGB/RGB ratio. We model the photometric data with a few sets of thermally pulsing AGB (TP-AGB) evolutionary models with different prescriptions for the mass loss. This technique allows us to set stringent constraints on the TP-AGB models of low-mass, metal-poor stars (with M sun , [Fe/H]∼ sun . This is also in good agreement with recent observations of white dwarf masses in the M4 old globular cluster. These constraints can be added to those already derived from Magellanic Cloud star clusters as important mileposts in the arduous process of calibrating AGB evolutionary models.

Transition towards DC micro grids: From an AC to a hybrid AC and DC energy infrastructure

Directory of Open Access Journals (Sweden)

Evi Ploumpidou

2017-12-01

Full Text Available Our electricity is predominantly powered by alternating current (AC, ever since the War of Currents ended in the favor of Nicola Tesla at the end of the 19th century. However, lots of the appliances we use, such as electronics and lights with light-emitting diode (LED technology, work internally on direct current (DC and it is projected that the number of these appliances will increase in the near future. Another contributor to the increase in DC consumption is the ongoing electrification of mobility (Electric Vehicles (EVs. At the same time, photovoltaics (PV generate DC voltages, while the most common storage technologies also use DC. In order to integrate all these appliances and technologies to the existing AC grid, there is a need for converters which introduce power losses. By distributing DC power to DC devices instead of converting it to AC first, it is possible to avoid substantial energy losses that occur every time electricity is converted. This situation initiated the concept for the implementation of the DC-Flexhouse project. A prototype DC installation will be developed and tested in one of the buildings of the developing living lab area called the District of Tomorrow (De Wijk van Morgen which is located in Heerlen, the Netherlands. A neighborhood cooperative (Vrieheide cooperatie is also part of the consortium in order to address the aspect of social acceptance. Although DC seems to be a promising solution for a more sustainable energy system, the business case is still debatable due to both technology- and market-related challenges. The current energy infrastructure is predominantly based on AC, manufacturers produce devices based on AC standards and people are using many AC products across a long life span. This Smart Energy Buildings & Cities (SEB&C PDEng project is a contribution to the DC-Flexhouse project. The aim is to analyze the challenges in the transition to DC micro grids, assess the market potential of DC

ACS and STEMI treatment: gender-related issues.

Science.gov (United States)

Chieffo, Alaide; Buchanan, Gill Louise; Mauri, Fina; Mehilli, Julinda; Vaquerizo, Beatriz; Moynagh, Anouska; Mehran, Roxana; Morice, Marie-Claude

2012-08-01

Cardiovascular disease is the leading cause of death amongst women, with acute coronary syndromes (ACS) representing a significant proportion. It has been reported that in women presenting with ACS there is underdiagnosis and consequent undertreatment leading to an increase in hospital and long-term mortality. Several factors have to be taken into account, including lack of awareness both at patient and at physician level. Women are generally not aware of the cardiovascular risk and symptoms, often atypical, and therefore wait longer to seek medical attention. In addition, physicians often underestimate the risk of ACS in women leading to a further delay in accurate diagnosis and timely appropriate treatment, including cardiac catheterisation and primary percutaneous coronary intervention, with consequent delayed revascularisation times. It has been acknowledged by the European Society of Cardiology that gender disparities do exist, with a Class I, Level of Evidence B recommendation that both genders should be treated in the same way when presenting with ACS. However, there is still a lack of awareness and the mission of Women in Innovation, in association with Stent for Life, is to change the perception of women with ACS and to achieve prompt diagnosis and treatment.

Intra-particle migration of mercury in granular polysulfide-rubber-coated activated carbon (PSR-AC)

Science.gov (United States)

Kim, Eun-Ah; Masue-Slowey, Yoko; Fendorf, Scott; Luthy, Richard G.

2011-01-01

The depth profile of mercuric ion after the reaction with polysulfide-rubber-coated activated carbon (PSR-AC) was investigated using micro-x-ray fluorescence (μ-XRF) imaging techniques and mathematical modeling. The μ-XRF results revealed that mercury was concentrated at 0~100 μm from the exterior of the particle after three months of treatment with PSR-AC in 10 ppm HgCl2 aqueous solution. The μ-X-ray absorption near edge spectroscopic (μ-XANES) analyses indicated HgS as a major mercury species, and suggested that the intra-particle mercury transport involved a chemical reaction with PSR polymer. An intra-particle mass transfer model was developed based on either a Langmuir sorption isotherm with liquid phase diffusion (Langmuir model) or a kinetic sorption with surface diffusion (kinetic sorption model). The Langmuir model predicted the general trend of mercury diffusion, although at a slower rate than observed from the μ-XRF map. A kinetic sorption model suggested faster mercury transport, which overestimated the movement of mercuric ions through an exchange reaction between the fast and slow reaction sites. Both μ-XRF and mathematical modeling results suggest mercury removal occurs not only at the outer surface of the PSR-AC particle but also at some interior regions due to a large PSR surface area within an AC particle. PMID:22133913

Intentional exposure to loud music: the second MTV.com survey reveals an opportunity to educate.

Science.gov (United States)

Quintanilla-Dieck, Maria de Lourdes; Artunduaga, Maria Alexandra; Eavey, Roland D

2009-10-01

Music-induced hearing loss (MIHL), an unconsciously self-inflicted public health concern, could evolve into an epidemic because of the appeal of loud music. After media attention about a previous hearing-loss survey with Music Television (MTV.com), we hypothesized that a repeat survey could compare awareness and behavior trends. We incorporated the 2002 survey into the new 73-question instrument presented to random visitors on the MTV.com website in 2007. A P music exposure. Health care providers were the least likely source of MIHL awareness despite the respondents favoring provider education for hearing protection behavior modification. Most respondents still could not recall learning about prevention of potential hearing loss, although the media has become the most informative source. Most respondents indicated that they would adopt protective ear behavior if made aware of hearing loss risk, especially if informed by health care professionals, revealing an educational opportunity.

Proteomics-based identification of midgut proteins correlated with Cry1Ac resistance in Plutella xylostella (L.).

Science.gov (United States)

Xia, Jixing; Guo, Zhaojiang; Yang, Zezhong; Zhu, Xun; Kang, Shi; Yang, Xin; Yang, Fengshan; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Xu, Weijun; Zhang, Youjun

2016-09-01

The diamondback moth, Plutella xylostella (L.), is a worldwide pest of cruciferous crops and can rapidly develop resistance to many chemical insecticides. Although insecticidal crystal proteins (i.e., Cry and Cyt toxins) derived from Bacillus thuringiensis (Bt) have been useful alternatives to chemical insecticides for the control of P. xylostella, resistance to Bt in field populations of P. xylostella has already been reported. A better understanding of the resistance mechanisms to Bt should be valuable in delaying resistance development. In this study, the mechanisms underlying P. xylostella resistance to Bt Cry1Ac toxin were investigated using two-dimensional differential in-gel electrophoresis (2D-DIGE) and ligand blotting for the first time. Comparative analyses of the constitutive expression of midgut proteins in Cry1Ac-susceptible and -resistant P. xylostella larvae revealed 31 differentially expressed proteins, 21 of which were identified by mass spectrometry. Of these identified proteins, the following fell into diverse eukaryotic orthologous group (KOG) subcategories may be involved in Cry1Ac resistance in P. xylostella: ATP-binding cassette (ABC) transporter subfamily G member 4 (ABCG4), trypsin, heat shock protein 70 (HSP70), vacuolar H(+)-ATPase, actin, glycosylphosphatidylinositol anchor attachment 1 protein (GAA1) and solute carrier family 30 member 1 (SLC30A1). Additionally, ligand blotting identified the following midgut proteins as Cry1Ac-binding proteins in Cry1Ac-susceptible P. xylostella larvae: ABC transporter subfamily C member 1 (ABCC1), solute carrier family 36 member 1 (SLC36A1), NADH dehydrogenase iron-sulfur protein 3 (NDUFS3), prohibitin and Rap1 GTPase-activating protein 1. Collectively, these proteomic results increase our understanding of the molecular resistance mechanisms to Bt Cry1Ac toxin in P. xylostella and also demonstrate that resistance to Bt Cry1Ac toxin is complex and multifaceted. Copyright © 2016 Elsevier B.V. All

Use of an AC/DC/AC Electrochemical Technique to Assess the Durability of Protection Systems for Magnesium Alloys

Science.gov (United States)

Song, Sen; McCune, Robert C.; Shen, Weidian; Wang, Yar-Ming

One task under the U.S. Automotive Materials Partnership (USAMP) "Magnesium Front End Research and Development" (MFERD) Project has been the evaluation of methodologies for the assessment of protective capability for a variety of proposed protection schemes for this hypothesized multi-material, articulated structure. Techniques which consider the entire protection system, including both pretreatments and topcoats are of interest. In recent years, an adaptation of the classical electrochemical impedance spectroscopy (EIS) approach using an intermediate cathodic DC polarization step (viz. AC/DC/AC) has been employed to accelerate breakdown of coating protection, specifically at the polymer-pretreatment interface. This work reports outcomes of studies to employ the AC/DC/AC approach for comparison of protective coatings to various magnesium alloys considered for front end structures. In at least one instance, the protective coating system breakdown could be attributed to the poorer intrinsic corrosion resistance of the sheet material (AZ31) relative to die-cast AM60B.

Should fee-for-service be for all guideline-advocated acute coronary syndrome (ACS) care? Observations from the Snapshot ACS study.

Science.gov (United States)

Briffa, Thomas G; Hammett, Christopher J; Cross, David B; Macisaac, Andrew I; Rankin, James M; Board, Neville; Carr, Bridie; Hyun, Karice K; French, John; Brieger, David B; Chew, Derek P

2015-09-01

The aim of the present study was to explore the association of health insurance status on the provision of guideline-advocated acute coronary syndrome (ACS) care in Australia. Consecutive hospitalisations of suspected ACS from 14 to 27 May 2012 enrolled in the Snapshot study of Australian and New Zealand patients were evaluated. Descriptive and logistic regression analysis was performed to evaluate the association of patient risk and insurance status with the receipt of care. In all, 3391 patients with suspected ACS from 247 hospitals (23 private) were enrolled in the present study. One-third of patients declared private insurance coverage; of these, 27.9% (304/1088) presented to private facilities. Compared with public patients, privately insured patients were more likely to undergo in-patient echocardiography and receive early angiography; furthermore, in those with a discharge diagnosis of ACS, there was a higher rate of revascularisation (P fee-for-service. In contrast, proportionately fewer privately insured ACS patients were discharged on selected guideline therapies and were referred to a secondary prevention program (P = 0.056), neither of which directly attracts a fee. Typically, as GRACE (the Global Registry of Acute Coronary Events) risk score rose, so did the level of ACS care; however, propensity-adjusted analyses showed lower in-hospital adverse events among the insured group (odds ratio 0.68; 95% confidence interval 0.52-0.88; P = 0.004). Fee-for-service reimbursement may explain differences in the provision of selected guideline-advocated components of ACS care between privately insured and public patients.

AC/RF Superconductivity

Energy Technology Data Exchange (ETDEWEB)

Ciovati, G [Jefferson Lab (United States)

2014-07-01

This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

AC/RF Superconductivity

Energy Technology Data Exchange (ETDEWEB)

Ciovati, Gianluigi [JLAB

2015-02-01

This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

Safe-commutation principle for direct single-phase AC-AC converters for use in audio power amplification

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.; Andersen, Michael A.E.

2005-07-01

This paper presents an alternative safe commutation principle for a single phase bidirectional bridge, for use in the new generation of direct single-stage AC-AC audio power amplifiers. As compared with the bridge commutation with load current or source voltage sensing, in this approach it is not required to do any measurements, thus making it more reliable. Initial testing made on the prototype prove the feasibility of the approach. (au)

Ac irreversibility line of bismuth-based high temperature superconductors

International Nuclear Information System (INIS)

Mehdaoui, A.; Beille, J.; Berling, D.; Loegel, B.; Noudem, J.G.; Tournier, R.

1997-01-01

We discuss the magnetic properties of lead doped Bi-2223 bulk samples obtained through combined magnetic melt texturing and hot pressing (MMTHP). The ac complex susceptibility measurements are achieved over a broad ac field range (1 Oe ac <100 Oe) and show highly anisotropic properties. The intergranular coupling is improved in the direction perpendicular to the applied stress and magnetic field direction, and an intragranular loss peak is observed for the first time. A comparison is made with other bismuth-based compounds and it is shown that the MMTHP process shifts the ac irreversibility line (ac IL) toward higher fields. It is also shown that all the ac IL close-quote s for quasi 2D bismuth-based compounds show a nearly quadratic temperature dependence and deviate therefore strongly from the linear behavior observed in quasi 3D compounds and expected from a critical state model.copyright 1997 Materials Research Society

Proteomic analysis of lysine acetylation sites in rat tissues reveals organ specificity and subcellular patterns

DEFF Research Database (Denmark)

Lundby, Alicia; Hansen, Kasper Lage; Weinert, Brian Tate

2012-01-01

,541 proteins and provide the data set as a web-based database. We demonstrate that lysine acetylation displays site-specific sequence motifs that diverge between cellular compartments, with a significant fraction of nuclear sites conforming to the consensus motifs G-AcK and AcK-P. Our data set reveals...

ACS-Hach Programs: Supporting Excellence in High School Chemistry Teaching

Science.gov (United States)

Taylor, Terri

2009-05-01

In January 2009, the ACS received a gift of approximately $33 million from the Hach Scientific Foundation, the largest gift in the society's 133-year history. The foundation's programs will be continued by the ACS and will complement pre-existing ACS resources that support high school chemistry teaching. Three activities serve as the pillars of the ACS-Hach programs—the High School Chemistry Grant Program, the Second Career Teacher Scholarship Program, and the Land Grant University Scholars Program. Collectively, the ACS-Hach programs support high school chemistry teaching and learning by responding to the needs of both in-service and pre-service secondary teachers. The goals of each of the ACS-Hach programs align well with the ACS Mission—to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people.

Two very long chain fatty acid acyl-CoA synthetase genes, acs-20 and acs-22, have roles in the cuticle surface barrier in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Eriko Kage-Nakadai

Full Text Available In multicellular organisms, the surface barrier is essential for maintaining the internal environment. In mammals, the barrier is the stratum corneum. Fatty acid transport protein 4 (FATP4 is a key factor involved in forming the stratum corneum barrier. Mice lacking Fatp4 display early neonatal lethality with features such as tight, thick, and shiny skin, and a defective skin barrier. These symptoms are strikingly similar to those of a human skin disease called restrictive dermopathy. FATP4 is a member of the FATP family that possesses acyl-CoA synthetase activity for very long chain fatty acids. How Fatp4 contributes to skin barrier function, however, remains to be elucidated. In the present study, we characterized two Caenorhabditis elegans genes, acs-20 and acs-22, that are homologous to mammalian FATPs. Animals with mutant acs-20 exhibited defects in the cuticle barrier, which normally prevents the penetration of small molecules. acs-20 mutant animals also exhibited abnormalities in the cuticle structure, but not in epidermal cell fate or cell integrity. The acs-22 mutants rarely showed a barrier defect, whereas acs-20;acs-22 double mutants had severely disrupted barrier function. Moreover, the barrier defects of acs-20 and acs-20;acs-22 mutants were rescued by acs-20, acs-22, or human Fatp4 transgenes. We further demonstrated that the incorporation of exogenous very long chain fatty acids into sphingomyelin was reduced in acs-20 and acs-22 mutants. These findings indicate that C. elegans Fatp4 homologue(s have a crucial role in the surface barrier function and this model might be useful for studying the fundamental molecular mechanisms underlying human skin barrier and relevant diseases.

Magnetic irreversibility in granular superconductors: ac susceptibility study

International Nuclear Information System (INIS)

Perez, F.; Obradors, X.; Fontcuberta, J.; Vallet, M.; Gonzalez-Calbet, J.

1991-01-01

Ac susceptibility measurements of a ceramic weak-coupled superconductor in very low ac fields (2mG, 111Hz) are reported. We present evidence for the observation of the magnetic irreversibility following a ZFC-FC thermal cycling by means of ac susceptibilty measurements. It is shown that this technique also reflect local magnetic field effects in granular superconductors, as previously suggested in microwave surface resistance and I-V characteristics. (orig.)

HOMOGENEOUS UGRIZ PHOTOMETRY FOR ACS VIRGO CLUSTER SURVEY GALAXIES: A NON-PARAMETRIC ANALYSIS FROM SDSS IMAGING

International Nuclear Information System (INIS)

Chen, Chin-Wei; Cote, Patrick; Ferrarese, Laura; West, Andrew A.; Peng, Eric W.

2010-01-01

We present photometric and structural parameters for 100 ACS Virgo Cluster Survey (ACSVCS) galaxies based on homogeneous, multi-wavelength (ugriz), wide-field SDSS (DR5) imaging. These early-type galaxies, which trace out the red sequence in the Virgo Cluster, span a factor of nearly ∼10 3 in g-band luminosity. We describe an automated pipeline that generates background-subtracted mosaic images, masks field sources and measures mean shapes, total magnitudes, effective radii, and effective surface brightnesses using a model-independent approach. A parametric analysis of the surface brightness profiles is also carried out to obtain Sersic-based structural parameters and mean galaxy colors. We compare the galaxy parameters to those in the literature, including those from the ACSVCS, finding good agreement in most cases, although the sizes of the brightest, and most extended, galaxies are found to be most uncertain and model dependent. Our photometry provides an external measurement of the random errors on total magnitudes from the widely used Virgo Cluster Catalog, which we estimate to be σ(B T )∼ 0.13 mag for the brightest galaxies, rising to ∼ 0.3 mag for galaxies at the faint end of our sample (B T ∼ 16). The distribution of axial ratios of low-mass ( d warf ) galaxies bears a strong resemblance to the one observed for the higher-mass ( g iant ) galaxies. The global structural parameters for the full galaxy sample-profile shape, effective radius, and mean surface brightness-are found to vary smoothly and systematically as a function of luminosity, with unmistakable evidence for changes in structural homology along the red sequence. As noted in previous studies, the ugriz galaxy colors show a nonlinear but smooth variation over a ∼7 mag range in absolute magnitude, with an enhanced scatter for the faintest systems that is likely the signature of their more diverse star formation histories.

Control of hybrid AC/DC microgrid under islanding operational conditions

DEFF Research Database (Denmark)

Ding, G.; Gao, F.; Zhang, S.

2014-01-01

This paper presents control methods for hybrid AC/DC microgrid under islanding operation condition. The control schemes for AC sub-microgrid and DC sub-microgrid are investigated according to the power sharing requirement and operational reliability. In addition, the key control schemes...... of interlinking converter with DC-link capacitor or energy storage, which will devote to the proper power sharing between AC and DC sub-microgrids to maintain AC and DC side voltage stable, is reviewed. Combining the specific control methods developed for AC and DC sub-microgrids with interlinking converter......, the whole hybrid AC/DC microgrid can manage the power flow transferred between sub-microgrids for improving on the operational quality and efficiency....

Ac irreversibility line of bismuth-based high temperature superconductors

Energy Technology Data Exchange (ETDEWEB)

Mehdaoui, A. [Laboratoire de Physique et de Spectroscopie Electronique, URA 1435 Faculte des Sciences, Universite de Haute Alsace 4, rue des Freres Lumiere, 68093 Mulhouse Cedex (France); Beille, J. [Laboratoire Louis Neel, CNRS, BP 166, 38042 Grenoble Cedex 9 (France); Berling, D.; Loegel, B. [Laboratoire de Physique et de Spectroscopie Electronique, URA 1435 Faculte des Sciences, Universite de Haute Alsace 4, rue des Freres Lumiere, 68093 Mulhouse Cedex (France); Noudem, J.G.; Tournier, R. [EPM-MATFORMAG, Laboratoire dElaboration par Procede Magnetique, CNRS, BP 166, 38042 Grenoble Cedex 9 (France)

1997-09-01

We discuss the magnetic properties of lead doped Bi-2223 bulk samples obtained through combined magnetic melt texturing and hot pressing (MMTHP). The ac complex susceptibility measurements are achieved over a broad ac field range (1 Oe{lt}h{sub ac}{lt}100 Oe) and show highly anisotropic properties. The intergranular coupling is improved in the direction perpendicular to the applied stress and magnetic field direction, and an intragranular loss peak is observed for the first time. A comparison is made with other bismuth-based compounds and it is shown that the MMTHP process shifts the ac irreversibility line (ac IL) toward higher fields. It is also shown that all the ac IL{close_quote}s for quasi 2D bismuth-based compounds show a nearly quadratic temperature dependence and deviate therefore strongly from the linear behavior observed in quasi 3D compounds and expected from a critical state model.{copyright} {ital 1997 Materials Research Society.}

Wind-powered asynchronous AC/DC/AC converter system. [for electric power supply regulation

Science.gov (United States)

Reitan, D. K.

1973-01-01

Two asynchronous ac/dc/ac systems are modelled that utilize wind power to drive a variable or constant hertz alternator. The first system employs a high power 60-hertz inverter tie to the large backup supply of the power company to either supplement them from wind energy, storage, or from a combination of both at a preset desired current; rectifier and inverter are identical and operate in either mode depending on the silicon control rectifier firing angle. The second system employs the same rectification but from a 60-hertz alternator arrangement; it provides mainly dc output, some sinusoidal 60-hertz from the wind bus and some high harmonic content 60-hertz from an 800-watt inverter.

A Case Study of Wind-PV-Thermal-Bundled AC/DC Power Transmission from a Weak AC Network

Science.gov (United States)

Xiao, H. W.; Du, W. J.; Wang, H. F.; Song, Y. T.; Wang, Q.; Ding, J.; Chen, D. Z.; Wei, W.

2017-05-01

Wind power generation and photovoltaic (PV) power generation bundled with the support by conventional thermal generation enables the generation controllable and more suitable for being sent over to remote load centre which are beneficial for the stability of weak sending end systems. Meanwhile, HVDC for long-distance power transmission is of many significant technique advantages. Hence the effects of wind-PV-thermal-bundled power transmission by AC/DC on power system have become an actively pursued research subject recently. Firstly, this paper introduces the technical merits and difficulties of wind-photovoltaic-thermal bundled power transmission by AC/DC systems in terms of meeting the requirement of large-scale renewable power transmission. Secondly, a system model which contains a weak wind-PV-thermal-bundled sending end system and a receiving end system in together with a parallel AC/DC interconnection transmission system is established. Finally, the significant impacts of several factors which includes the power transmission ratio between the DC and AC line, the distance between the sending end system and receiving end system, the penetration rate of wind power and the sending end system structure on system stability are studied.

Small-Signal Analysis of Single-Phase and Three-phase DC/AC and AC/DC PWM Converters with the Frequency-Shift Technique

DEFF Research Database (Denmark)

Blaabjerg, Frede; Aquila, A. Dell’; Liserre, Marco

2004-01-01

of dc/dc converters via a 50 Hz frequency-shift. The input admittance is calculated and measured for two study examples (a three-phase active rectifier and a single-phase photovoltaic inverter). These examples show that the purpose of a well designed controller for grid-connected converters......A systematic approach to study dc/ac and ac/dc converters without the use of synchronous transformation is proposed. The use of a frequency-shift technique allows a straightforward analysis of single-phase and three-phase systems. The study of dc/ac and of ac/dc converters is reported to the study...... is to minimize the input admittance in order to make the grid converter more robust to grid disturbance....

21 CFR 880.5100 - AC-powered adjustable hospital bed.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered adjustable hospital bed. 880.5100 Section 880.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered...

Nonlinear AC susceptibility, surface and bulk shielding

Science.gov (United States)

van der Beek, C. J.; Indenbom, M. V.; D'Anna, G.; Benoit, W.

1996-02-01

We calculate the nonlinear AC response of a thin superconducting strip in perpendicular field, shielded by an edge current due to the geometrical barrier. A comparison with the results for infinite samples in parallel field, screened by a surface barrier, and with those for screening by a bulk current in the critical state, shows that the AC response due to a barrier has general features that are independent of geometry, and that are significantly different from those for screening by a bulk current in the critical state. By consequence, the nonlinear (global) AC susceptibility can be used to determine the origin of magnetic irreversibility. A comparison with experiments on a Bi 2Sr 2CaCu 2O 8+δ crystal shows that in this material, the low-frequency AC screening at high temperature is mainly due to the screening by an edge current, and that this is the unique source of the nonlinear magnetic response at temperatures above 40 K.

AC BREAKDOWN IN GASES

Science.gov (United States)

electron- emission (multipactor) region, and (3) the low-frequency region. The breakdown mechanism in each of these regions is explained. An extensive bibliography on AC breakdown in gases is included.

Assessing the allelotypic effect of two aminocyclopropane carboxylic acid synthase-encoding genes MdACS1 and MdACS3a on fruit ethylene production and softening in Malus

Science.gov (United States)

Dougherty, Laura; Zhu, Yuandi; Xu, Kenong

2016-01-01

Phytohormone ethylene largely determines apple fruit shelf life and storability. Previous studies demonstrated that MdACS1 and MdACS3a, which encode 1-aminocyclopropane-1-carboxylic acid synthases (ACS), are crucial in apple fruit ethylene production. MdACS1 is well-known to be intimately involved in the climacteric ethylene burst in fruit ripening, while MdACS3a has been regarded a main regulator for ethylene production transition from system 1 (during fruit development) to system 2 (during fruit ripening). However, MdACS3a was also shown to have limited roles in initiating the ripening process lately. To better assess their roles, fruit ethylene production and softening were evaluated at five time points during a 20-day post-harvest period in 97 Malus accessions and in 34 progeny from 2 controlled crosses. Allelotyping was accomplished using an existing marker (ACS1) for MdACS1 and two markers (CAPS866 and CAPS870) developed here to specifically detect the two null alleles (ACS3a-G289V and Mdacs3a) of MdACS3a. In total, 952 Malus accessions were allelotyped with the three markers. The major findings included: The effect of MdACS1 was significant on fruit ethylene production and softening while that of MdACS3a was less detectable; allele MdACS1–2 was significantly associated with low ethylene and slow softening; under the same background of the MdACS1 allelotypes, null allele Mdacs3a (not ACS3a-G289V) could confer a significant delay of ethylene peak; alleles MdACS1–2 and Mdacs3a (excluding ACS3a-G289V) were highly enriched in M. domestica and M. hybrid when compared with those in M. sieversii. These findings are of practical implications in developing apples of low and delayed ethylene profiles by utilizing the beneficial alleles MdACS1-2 and Mdacs3a. PMID:27231553

AC electric motors control advanced design techniques and applications

CERN Document Server

Giri, Fouad

2013-01-01

The complexity of AC motor control lies in the multivariable and nonlinear nature of AC machine dynamics. Recent advancements in control theory now make it possible to deal with long-standing problems in AC motors control. This text expertly draws on these developments to apply a wide range of model-based control designmethods to a variety of AC motors. Contributions from over thirty top researchers explain how modern control design methods can be used to achieve tight speed regulation, optimal energetic efficiency, and operation reliability and safety, by considering online state var

Ac conductivity and relaxation mechanism in Ba0.9Sr0.1TiO3

International Nuclear Information System (INIS)

Singh, A.K.; Barik, Subrat K.; Choudhary, R.N.P.; Mahapatra, P.K.

2009-01-01

The ac conductivity and relaxation mechanism in Ba 0.9 Sr 0.1 TiO 3 ceramics have been investigated systematically. A high-temperature solid-state reaction technique was used to synthesize the compound. The formation of the compound was checked by an X-ray diffraction (XRD) technique. The dielectric permittivity and the loss tangent of the sample were measured in a frequency range from 1 kHz to 1 MHz at different temperatures (30-500 deg. C). A study on dielectric properties reveals the electrical relaxation phenomenon occurs in the material. The activation energy was calculated from the temperature variation of dc conductivity. Studies of frequency and temperature dependence of ac conductivity of the compound suggest that conduction process in the material is thermally activated.

Pengembangan Sistem Otomatisasi AC dan Lampu Menggunakan Fuzzy dan Raspberry Pi

Directory of Open Access Journals (Sweden)

Rudy Ariyanto

2017-11-01

Full Text Available Otomatisasi AC dan lampu dilakukan untuk menghemat energi yang digunakan pada kehidupan sehari-hari. Dalam pengembangan otomatisasi AC dan lampu perlu menerapkan sebuah perangkat yang memiliki fungsi maksimal dengan harga yang minimal. Raspberry Pi merupakan perangkat atau modul dengan harga rendah yang mampu melakukan komunikasi wireless tanpa bantuan modul lain. Dalam pengembangan otomatisasi AC dan lampu juga diperlukan sebuah metode yang mampu melakukan kontrol terhadap nyala AC dan lampu. Penerapan metode fuzzy dapat dilakukan untuk menghimpun informasi keadaan ruang yang didapat dari sensor untuk menentukan nyala AC dan lampu secara otomatis. Oleh sebab itu pada penelitian ini mengusulkan pengembangan otomatisasi AC dan lampu menggunakan Raspberry Pi dan Fuzzy. Otomatisasi AC dan lampu menggunakan Raspberry Pi yang menerapkan metode Fuzzy dapat menghemat energi hingga 59,87% dalam hal lama waktu nyala AC dan 57,47% untuk lumenasi lampu

Successful enrichment of the ubiquitous freshwater acI Actinobacteria.

Science.gov (United States)

Garcia, Sarahi L; McMahon, Katherine D; Grossart, Hans-Peter; Warnecke, Falk

2014-02-01

Actinobacteria of the acI lineage are often the numerically dominant bacterial phylum in surface freshwaters, where they can account for > 50% of total bacteria. Despite their abundance, there are no described isolates. In an effort to obtain enrichment of these ubiquitous freshwater Actinobacteria, diluted freshwater samples from Lake Grosse Fuchskuhle, Germany, were incubated in 96-well culture plates. With this method, a successful enrichment containing high abundances of a member of the lineage acI was established. Phylogenetic classification showed that the acI Actinobacteria of the enrichment belonged to the acI-B2 tribe, which seems to prefer acidic lakes. This enrichment grows to low cell densities and thus the oligotrophic nature of acI-B2 was confirmed. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Spectroscopic Observations and Analysis of the Unusual Type Ia SN1999ac

International Nuclear Information System (INIS)

Garavini, G.; Aldering, G.; Amadon, A.; Amanullah, R.; Astier, P.; Balland, C.; Blanc, G.; Conley, A.; Dahlen, T.; Deustua, S.E.; Ellis, R.; Fabbro, S.; Fadeyev, V.; Fan, X.; Folatelli, G.; Frye, B.; Gates, E.L.; Gibbons, R.; Goldhaber, G.; Goldman, B.; Goobar, A.; Groom, D.E.; Haissinski, J.; Hardin, D.; Hook, I.; Howell, D.A.; Kent, S.; Kim, A.G.; Knop, R.A.; Kowalski, M.; Kuznetsova, N.; Lee, B.C.; Lidman, C.; Mendez, J.; Miller, G.J.; Moniez, M.; Mouchet, M.; Mourao, A.; Newberg, H.; Nobili, S.; Nugent, P.E.; Pain, R.; Perdereau, O.; Perlmutter, S.; Quimby, R.; Regnault, N.; Rich, J.; Richards, G.T.; Ruiz-Lapuente, P.; Schaefer, B.E.; Schahmaneche, K.; Smith, E.; Spadafora, A.L.; Stanishev, V.; Thomas, R.C.; Walton, N.A.; Wang, L.; Wood-Vasey, W.M.

2005-01-01

The authors present optical spectra of the peculiar Type Ia supernova (SN Ia) 1999ac. The data extend from -15 to +42 days with respect to B-band maximum and reveal an event that is unusual in several respects. prior to B-band maximum, the spectra resemble those of SN 1999aa, a slowly declining event, but possess stronger Si II and Ca II signatures (more characteristic of a spectroscopically normal SN). Spectra after B-band maximum appear more normal. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from Si II are among the slowest ever observed, though SN 1999ac is not particularly dim. The analysis of the parameters v 10 (Si II), R(Si II), v, and Δm 15 further underlines the unique characteristics of SN 1999ac. They find convincing evidence of C II λ6580 in the day -15 spectrum with ejection velocity v > 16,000 km s -1 , but this signature disappears by day -9. This rapid evolution at early times highlights the importance of extremely early-time spectroscopy

Molecular cloning and construction of the coding region for human acetylcholinesterase reveals a G + C-rich attenuating structure

International Nuclear Information System (INIS)

Soreq, H.; Ben-Aziz, R.; Prody, C.A.; Seidman, S.; Gnatt, A.; Neville, L.; Lieman-Hurwitz, J.; Lev-Lehman, E.; Ginzberg, D.; Lapidot-Lifson, Y.; Zakut, H.

1990-01-01

To study the primary structure of human acetylcholinesterase and its gene expression and amplification, cDNA libraries from human tissues expressing oocyte-translatable AcChoEase mRNA were constructed and screened with labeled oligodeoxynucleotide probes. Several cDNA clones were isolated that encoded a polypeptide with ≥50% identically aligned amino acids to Torpedo AcChoEase and human butyrylcholinesterase. However, these cDNA clones were all truncated within a 300-nucleotide-long G + C-rich region with a predicted pattern of secondary structure having a high Gibbs free energy downstream from the expected 5' end of the coding region. Screening of a genomic DNA library revealed the missing 5' domain. When ligated to the cDNA and constructed into a transcription vector, this sequence encoded a synthetic mRNA translated in microinjected oocytes into catalytically active AcChoEase with marked preference for acetylthiocholine over butyrylthiocholine as a substrate, susceptibility to inhibition by the AcChoEase inhibitor BW284C51, and resistance to the AcChoEase inhibitor tetraisopropylpyrophosphoramide. Blot hybridization of genomic DNA from different individuals carrying amplified AcChoEase genes revealed variable intensities and restriction patterns with probes from the regions upstream and downstream from the predicted G + C-rich structure. Thus, the human AcChoEase gene includes a putative G + C-rich attenuator domain and is subject to structural alterations in cases of AcChoEase gene amplification

AcEST(EST sequences of Adiantum capillus-veneris and their annotation) - AcEST | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available List Contact us AcEST AcEST(EST sequences of Adiantum capillus-veneris and their annotation) Data detail Dat...a name AcEST(EST sequences of Adiantum capillus-veneris and their annotation) DOI 10.18908/lsdba.nbdc00839-0...01 Description of data contents EST sequence of Adiantum capillus-veneris and its annotation (clone ID, libr...le search URL http://togodb.biosciencedbc.jp/togodb/view/archive_acest#en Data acquisition method Capillary ...ainst UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases) Number of data entries Adiantum capillus-veneris

Design and synthesis of 225Ac radioimmunopharmaceuticals

International Nuclear Information System (INIS)

McDevitt, Michael R.; Ma, Dangshe; Simon, Jim; Frank, R. Keith; Scheinberg, David A.

2002-01-01

The alpha-particle-emitting radionuclides 213 Bi, 211 At, 224 Ra are under investigation for the treatment of leukemias, gliomas, and ankylosing spondylitis, respectively. 213 Bi and 211 At were attached to monoclonal antibodies and used as targeted immunotherapeutic agents while unconjugated 224 Ra chloride selectively seeks bone. 225 Ac possesses favorable physical properties for radioimmunotherapy (10 d half-life and 4 net alpha particles), but has a history of unfavorable radiolabeling chemistry and poor metal-chelate stability. We selected functionalized derivatives of DOTA as the most promising to pursue from out of a group of potential 225 Ac chelate compounds. A two-step synthetic process employing either MeO-DOTA-NCS or 2B-DOTA-NCS as the chelating moiety was developed to attach 225 Ac to monoclonal antibodies. This method was tested using several different IgG systems. The chelation reaction yield in the first step was 93±8% radiochemically pure (n=26). The second step yielded 225 Ac-DOTA-IgG constructs that were 95±5% radiochemically pure (n=27) and the mean percent immunoreactivity ranged from 25% to 81%, depending on the antibody used. This process has yielded several potential novel targeted 225 Ac-labeled immunotherapeutic agents that may now be evaluated in appropriate model systems and ultimately in humans

Nuclear structure of 231Ac

International Nuclear Information System (INIS)

Boutami, R.; Borge, M.J.G.; Mach, H.; Kurcewicz, W.; Fraile, L.M.; Gulda, K.; Aas, A.J.; Garcia-Raffi, L.M.; Lovhoiden, G.; Martinez, T.; Rubio, B.; Tain, J.L.; Tengblad, O.

2008-01-01

The low-energy structure of 231 Ac has been investigated by means of γ ray spectroscopy following the β - decay of 231 Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a MINI-ORANGE electron spectrometer. The decay scheme of 231 Ra → 231 Ac has been constructed for the first time. The Advanced Time Delayed βγγ(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus

Marketingová komunikace AC Sparta Praha

OpenAIRE

Fanta, Jan

2016-01-01

Title: Marketing communications of AC Sparta Praha Objectives: The main objective of this thesis is to analyze contemporary state of marketing communications with the audience of AC Sparta Praha, identify deficiencies and develop a proposal to improve the marketing communications with fans of this club. Methods: In this thesis have been used methods of case study, analysis of available documents and texts, structured interview with director od marketing, and director of communications and pub...

c-axis ac susceptibility in high-Tc superconductors

International Nuclear Information System (INIS)

Waldmann, O.; Lichtschlag, G.; Talalaevskii, A.; Kleiner, R.; Mueller, P.; Steinmeyer, F.; Gerhaeuser, W.

1996-01-01

We have investigated the angle and magnetic field dependence of the ac susceptibility in Bi 2 Sr 2 CaCu 2 O 8 and YBa 2 Cu 3 O 7 single crystals at low external fields. The ac field was applied perpendicular to the CuO 2 planes. The first and third harmonics of the ac susceptibility exhibit remarkably sharp features when the dc field component perpendicular to the CuO 2 planes passes a threshold field H th . H th is strongly temperature dependent, but is independent of the parallel field component. We propose a simple model which excellently explains the data. Within this model the peak structures are related to the irreversibility line. We discuss the implications of the model for the interpretation of the ac susceptibility. copyright 1996 The American Physical Society

Fast electric dipole transitions in Ra-Ac nuclei

International Nuclear Information System (INIS)

Ahmad, I.

1985-01-01

Lifetime of levels in 225 Ra, 225 Ac, and 227 Ac have been measured by delayed coincidence techniques and these have been used to determine the E1 gamma-ray transition probabilities. The reduced E1 transition probabilities. The reduced E1 transition probabilities in 225 Ra and 225 Ac are about two orders of magnitude larger than the values in mid-actinide nuclei. On the other hand, the E1 rate in 227 Ac is similar to those measured in heavier actinides. Previous studies suggest the presence of octupole deformation in all the three nuclei. The present investigation indicates that fast E1 transitions occur for nuclei with octupole deformation. However, the studies also show that there is no one-to-one correspondence between E1 rate and octupole deformation. 13 refs., 4 figs

Pittsburgh American Community Survey Data 2015 - Household Types

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The data on relationship to householder were derived from answers to Question 2 in the 2015 American Community Survey (ACS), which was asked of all people in...

Nutrition, Physical Activity, and Obesity - American Community Survey

Data.gov (United States)

U.S. Department of Health & Human Services — This dataset includes select data from the U.S. Census Bureau's American Community Survey (ACS) on the percent of adults who bike or walk to work. This data is used...

Puerto Rico Revealed Preference Survey Data 2004

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Revealed preference models provide insights into recreational angler behavior and the economic value of recreational fishing trips. Revealed preference data is...

Advanced DC/AC inverters applications in renewable energy

CERN Document Server

Luo, Fang Lin

2013-01-01

DC/AC inversion technology is of vital importance for industrial applications, including electrical vehicles and renewable energy systems, which require a large number of inverters. In recent years, inversion technology has developed rapidly, with new topologies improving the power factor and increasing power efficiency. Proposing many novel approaches, Advanced DC/AC Inverters: Applications in Renewable Energy describes advanced DC/AC inverters that can be used for renewable energy systems. The book introduces more than 100 topologies of advanced inverters originally developed by the authors,

A single-phase embedded Z-source DC-AC inverter.

Science.gov (United States)

Kim, Se-Jin; Lim, Young-Cheol

2014-01-01

In the conventional DC-AC inverter consisting of two DC-DC converters with unipolar output capacitors, the output capacitor voltages of the DC-DC converters must be higher than the DC input voltage. To overcome this weakness, this paper proposes a single-phase DC-AC inverter consisting of two embedded Z-source converters with bipolar output capacitors. The proposed inverter is composed of two embedded Z-source converters with a common DC source and output AC load. Though the output capacitor voltages of the converters are relatively low compared to those of a conventional inverter, an equivalent level of AC output voltages can be obtained. Moreover, by controlling the output capacitor voltages asymmetrically, the AC output voltage of the proposed inverter can be higher than the DC input voltage. To verify the validity of the proposed inverter, experiments were performed with a DC source voltage of 38 V. By controlling the output capacitor voltages of the converters symmetrically or asymmetrically, the proposed inverter can produce sinusoidal AC output voltages. The experiments show that efficiencies of up to 95% and 97% can be achieved with the proposed inverter using symmetric and asymmetric control, respectively.

Engineering cotton (Gossypium hirsutum L.) for resistance to cotton leaf curl disease using viral truncated AC1 DNA sequences.

Science.gov (United States)

Hashmi, Jamil A; Zafar, Yusuf; Arshad, Muhammad; Mansoor, Shahid; Asad, Shaheen

2011-04-01

Several important biological processes are performed by distinct functional domains found on replication-associated protein (Rep) encoded by AC1 of geminiviruses. Two truncated forms of replicase (tAC1) gene, capable of expressing only the N-terminal 669 bp (5'AC1) and C-terminal 783 bp (3'AC1) nucleotides cloned under transcriptional control of the CaMV35S were introduced into cotton (Gossypium hirsutum L.) using LBA4404 strain of Agrobacterium tumefaciens to make use of an interference strategy for impairing cotton leaf curl virus (CLCuV) infection in transgenic cotton. Compared with nontransformed control, we observed that transgenic cotton plants overexpressing either N-terminal (5'AC1) or C-terminal (3'AC1) sequences confer resistance to CLCuV by inhibiting replication of viral genomic and β satellite DNA components. Molecular analysis by Northern blot hybridization revealed high transgene expression in early and late growth stages associated with inhibition of CLCuV replication. Of the eight T(1) transgenic lines tested, six had delayed and minor symptoms as compared to nontransformed control lines which developed disease symptoms after 2-3 weeks of whitefly-mediated viral delivery. Virus biological assay and growth of T(2) plants proved that transgenic cotton plants overexpressing 5'- and 3'AC1 displayed high resistance level up to 72, 81%, respectively, as compared to non-transformed control plants following inoculation with viruliferous whiteflies giving significantly high cotton seed yield. Progeny analysis of these plants by polymerase chain reaction (PCR), Southern blotting and virus biological assay showed stable transgene, integration, inheritance and cotton leaf curl disease (CLCuD) resistance in two of the eight transgenic lines having single or two transgene insertions. Transgenic cotton expressing partial AC1 gene of CLCuV can be used as virus resistance source in cotton breeding programs aiming to improve virus resistance in cotton crop.

dc Arc Fault Effect on Hybrid ac/dc Microgrid

Science.gov (United States)

Fatima, Zahra

The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.

CPT Special Report: Survey of Ph.D. Programs in Chemistry.

Science.gov (United States)

Journal of Chemical Education, 1997

1997-01-01

Presents preliminary results from a survey taken by the American Chemical Society (ACS) Committee on Professional Training (CPT) to determine the current practices among 155 Ph.D. programs in chemistry. (DKM)

Frequency-dependent tACS modulation of BOLD signal during rhythmic visual stimulation.

Science.gov (United States)

Chai, Yuhui; Sheng, Jingwei; Bandettini, Peter A; Gao, Jia-Hong

2018-05-01

Transcranial alternating current stimulation (tACS) has emerged as a promising tool for modulating cortical oscillations. In previous electroencephalogram (EEG) studies, tACS has been found to modulate brain oscillatory activity in a frequency-specific manner. However, the spatial distribution and hemodynamic response for this modulation remains poorly understood. Functional magnetic resonance imaging (fMRI) has the advantage of measuring neuronal activity in regions not only below the tACS electrodes but also across the whole brain with high spatial resolution. Here, we measured fMRI signal while applying tACS to modulate rhythmic visual activity. During fMRI acquisition, tACS at different frequencies (4, 8, 16, and 32 Hz) was applied along with visual flicker stimulation at 8 and 16 Hz. We analyzed the blood-oxygen-level-dependent (BOLD) signal difference between tACS-ON vs tACS-OFF, and different frequency combinations (e.g., 4 Hz tACS, 8 Hz flicker vs 8 Hz tACS, 8 Hz flicker). We observed significant tACS modulation effects on BOLD responses when the tACS frequency matched the visual flicker frequency or the second harmonic frequency. The main effects were predominantly seen in regions that were activated by the visual task and targeted by the tACS current distribution. These findings bridge different scientific domains of tACS research and demonstrate that fMRI could localize the tACS effect on stimulus-induced brain rhythms, which could lead to a new approach for understanding the high-level cognitive process shaped by the ongoing oscillatory signal. © 2018 Wiley Periodicals, Inc.

Apple MdACS6 Regulates Ethylene Biosynthesis During Fruit Development Involving Ethylene-Responsive Factor.

Science.gov (United States)

Li, Tong; Tan, Dongmei; Liu, Zhi; Jiang, Zhongyu; Wei, Yun; Zhang, Lichao; Li, Xinyue; Yuan, Hui; Wang, Aide

2015-10-01

Ethylene biosynthesis in plants involves different 1-aminocyclopropane-1-carboxylic acid synthase (ACS) genes. The regulation of each ACS gene during fruit development is unclear. Here, we characterized another apple (Malus×domestica) ACS gene, MdACS6. The transcript of MdACS6 was observed not only in fruits but also in other tissues. During fruit development, MdACS6 was initiated at a much earlier stage, whereas MdACS3a and MdACS1 began to be expressed at 35 d before harvest and immediateley after harvest, respectively. Moreover, the enzyme activity of MdACS6 was significantly lower than that of MdACS3a and MdACS1, accounting for the low ethylene biosynthesis in young fruits. Overexpression of MdACS6 (MdACS6-OE) by transient assay in apple showed enhanced ethylene production, and MdACS3a was induced in MdACS6-OE fruits but not in control fruits. In MdACS6 apple fruits silenced by the virus-induced gene silencing (VIGS) system (MdACS6-AN), neither ethylene production nor MdACS3a transcript was detectable. In order to explore the mechanism through which MdACS3a was induced in MdACS6-OE fruits, we investigated the expression of apple ethylene-responsive factor (ERF) genes. The results showed that the expression of MdERF2 was induced in MdACS6-OE fruits and inhibited in MdACS6-AN fruits. Yeast one-hybrid assay showed that MdERF2 protein could bind to the promoter of MdACS3a. Moreover, down-regulation of MdERF2 in apple flesh callus led to a decrease of MdACS3a expression, demonstrating the regulation of MdERF2 on MdACS3a. The mechanism through which MdACS6 regulates the action of MdACS3a was discussed. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Self-discharge of AC/AC electrochemical capacitors in salt aqueous electrolyte

International Nuclear Information System (INIS)

García-Cruz, L.; Ratajczak, P.; Iniesta, J.; Montiel, V.; Béguin, F.

2016-01-01

The self-discharge (SD) of electrochemical capacitors based on activated carbon electrodes (AC/AC capacitors) in aqueous lithium sulfate was examined after applying a three-hour cell potential hold at U i values from 1.0 to 1.6 V. The leakage current measured during the potentiostatic period as well as the amplitude of self-discharge increased with U i ; the cell potential drop was approximately doubled by 10 °C increase of temperature. The potential decay of both negative and positive electrodes was explored separately, by introducing a reference electrode and it was found that the negative electrode contributes essentially to the capacitor self-discharge. A diffusion-controlled mechanism was found at U i ≤ 1.4 V and U i ≤ 1.2 V for the positive and negative electrodes, respectively. At higher U i of 1.6 V, both electrodes display an activation-controlled mechanism due to water oxidation and subsequent carbon oxidation at the positive electrode and water or oxygen reduction at the negative electrode.

Superconducting three element synchronous ac machine

International Nuclear Information System (INIS)

Boyer, L.; Chabrerie, J.P.; Mailfert, A.; Renard, M.

1975-01-01

There is a growing interest in ac superconducting machines. Of several new concepts proposed for these machines in the last years one of the most promising seems to be the ''three elements'' concept which allows the cancellation of the torque acting on the superconducting field winding, thus overcoming some of the major contraints. This concept leads to a device of induction-type generator. A synchronous, three element superconducting ac machine is described, in which a room temperature, dc fed rotating winding is inserted between the superconducting field winding and the ac armature. The steady-state machine theory is developed, the flux linkages are established, and the torque expressions are derived. The condition for zero torque on the field winding, as well as the resulting electrical equations of the machine, are given. The theoretical behavior of the machine is studied, using phasor diagrams and assuming for the superconducting field winding either a constant current or a constant flux condition

In-silico determination of insecticidal potential of Vip3Aa-Cry1Ac fusion protein against Lepidopteran targets using molecular docking

Directory of Open Access Journals (Sweden)

Aftab eAhmad

2015-12-01

Full Text Available Study and research of Bt (Bacillus thuringiensis transgenic plants have opened new ways to combat insect pests. Over the decades, however, insect pests, especially the Lepidopteran, have developed tolerance against Bt delta-endotoxins. Such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. In this computational study, functional domains of Bacillus thuringiensis crystal delta-endotoxin (Cry1Ac insecticidal protein and vegetative insecticidal protein (Vip3Aa have been fused to develop a broad-range Vip3Aa-Cry1Ac fusion protein. Cry1Ac and Vip3Aa are non-homologous insecticidal proteins possessing receptors against different targets within the midgut of insects. The insecticidal proteins were fused to broaden the insecticidal activity. Molecular docking analysis of the fusion protein against aminopeptidase-N (APN and cadherin receptors of five Lepidopteran insects (Agrotis ipsilon, Helicoverpa armigera, Pectinophora gossypiella, Spodoptera exigua and Spodoptera litura revealed that the Ser290, Ser293, Leu337, Thr340 and Arg437 residues of the fusion protein are involved in the interaction with insect receptors. The Helicoverpa armigera cadherin receptor, however, showed no interaction, which might be due to either loss or burial of interactive residues inside the fusion protein. These findings revealed that the Vip3Aa-Cry1Ac fusion protein has a strong affinity against Lepidopteran insect receptors and hence has a potential to be an efficient broad-range insecticidal protein.

Nontrivial ac spin response in the effective Luttinger model

International Nuclear Information System (INIS)

Hu Liangbin; Zhong Jiansong; Hu Kaige

2006-01-01

Based on the three-dimensional effective Luttinger Hamiltonian and the exact Heisenberg equations of motion and within a self-consistent semiclassical approximation, we present a theoretical investigation on the nontrivial ac spin responses due to the intrinsic spin-orbit coupling of holes in p-doped bulk semiconductors. We show that the nontrivial ac spin responses induced by the combined action of an ac external electric field and the intrinsic spin-orbit coupling of holes may lead to the generation of a nonvanishing ac spin Hall current in a p-doped bulk semiconductor, which shares some similarities with the dissipationless dc spin Hall current conceived previously and also exhibits some interesting new features that was not found before

A Heavy Metal-Associated Protein (AcHMA1 from the Halophyte, Atriplex canescens (Pursh Nutt., Confers Tolerance to Iron and Other Abiotic Stresses When Expressed in Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Xin-Hua Sun

2014-08-01

Full Text Available Many heavy metals are essential for metabolic processes, but are toxic at elevated levels. Metal tolerance proteins provide resistance to this toxicity. In this study, we identified and characterized a heavy metal-associated protein, AcHMA1, from the halophyte, Atriplex canescens. Sequence analysis has revealed that AcHMA1 contains two heavy metal binding domains. Treatments with metals (Fe, Cu, Ni, Cd or Pb, PEG6000 and NaHCO3 highly induced AcHMA1 expression in A. canescens, whereas NaCl and low temperature decreased its expression. The role of AcHMA1 in metal stress tolerance was examined using a yeast expression system. Expression of the AcHMA1 gene significantly increased the ability of yeast cells to adapt to and recover from exposure to excess iron. AcHMA1 expression also provided salt, alkaline, osmotic and oxidant stress tolerance in yeast cells. Finally, subcellular localization of an AcHMA1/GFP fusion protein expressed in tobacco cells showed that AcHMA1 was localized in the plasma membrane. Thus, our results suggest that AcHMA1 encodes a membrane-localized metal tolerance protein that mediates the detoxification of iron in eukaryotes. Furthermore, AcHMA1 also participates in the response to abiotic stress.

Performance Analysis of Phase Controlled Unidirectional and Bidirectional AC Voltage Controllers

Directory of Open Access Journals (Sweden)

Abdul Sattar Larik

2011-01-01

Full Text Available AC voltage controllers are used to vary the output ac voltage from a fixed ac input source. They are also commonly called ac voltage regulators or ac choppers. The output voltage is either controlled by PAC (Phase Angle Control method or on-off control method. Due to various advantages of ac voltage controllers, such as high efficiency, simplicity, low cost and ability to control large amount of power they efficiently control the speed of ac motors, light dimming and industrial heating, etc. These converters are variable structure systems and generate harmonics during the operation which will affect the power quality when connected to system network. During the last couple of years, a number of new semiconductor devices and various power electronic converters has been introduced. Accordingly the subject of harmonics and its problems are of great concern to power industry and customers. In this research work, initially the simulation models of single phase unidirectional and bidirectional ac voltage controllers were developed by using MATLAB software. The harmonics of these models are investigated by simulation. In the end, the harmonics were also analyzed experimentally. The simulated as well as experimental results are presented.

Overexpression of LncRNA AC067945.2 Down-Regulates Collagen Expression in Skin Fibroblasts and Possibly Correlates with the VEGF and Wnt Signalling Pathways.

Science.gov (United States)

Chen, Ling; Li, Jingyun; Li, Qian; Li, Xue; Gao, Yanli; Hua, Xiangdong; Zhou, Bei; Li, Jun

2018-01-01

Long non-coding RNAs (lncRNAs) are thought to play crucial roles in human diseases. However, the function of lncRNAs in hypertrophic scar formation remains poorly understood. Utilizing qRT-PCR, we explored the expression changes of AC067945.2. Overexpression of AC067945.2 in normal skin fibroblasts was performed by transient plasmid transfection. Western blot was used to check the proteins' expression changes. Cell Counting Kit-8 (CCK-8) assay and Annexin V/7-AAD staining were used to examine cell proliferation and apoptosis, respectively. mRNA-seq was applied to dissect the differentially expressed mRNAs in AC067945.2 overexpressed cells. We also performed ELISA to detect the VEGF secretion. AC067945.2 was down-regulated in hypertrophic scar tissues. Overexpression of AC067945.2 did not affect cell proliferation, but it mildly promoted early apoptosis in normal skin fibroblasts. Furthermore, AC067945.2 overexpression inhibited the expression of COL1A1, COL1A2, COL3A1 and α-SMA proteins. Transforming growth factor-β1 (TGF-β1) could inhibit the expression of AC067945.2. Based on mRNA-seq data, compared with mRNAs in the control group, 138 mRNAs were differentially expressed, including 14 up-regulated and 124 down-regulated transcripts, in the AC067945.2 overexpression group. Gene ontology and pathway analyses revealed that AC067945.2 overexpression was correlated with developmental processes, binding, extracellular region, and the vascular endothelial cell growth factor (VEGF) and Wnt signalling pathways. ELISA confirmed that AC067945.2 overexpression could repress VEGF secretion. Taken together, our data uncovered the functions of a novel lncRNA AC067945.2, which might help us understand the mechanisms regulated by AC067945.2 in the pathogenesis of hypertrophic scar formation. © 2018 The Author(s). Published by S. Karger AG, Basel.

Importance of Attenuation Correction (AC) for Small Animal PET Imaging

DEFF Research Database (Denmark)

El Ali, Henrik H.; Bodholdt, Rasmus Poul; Jørgensen, Jesper Tranekjær

2012-01-01

was performed. Methods: Ten NMRI nude mice with subcutaneous implantation of human breast cancer cells (MCF-7) were scanned consecutively in small animal PET and CT scanners (MicroPETTM Focus 120 and ImTek’s MicroCATTM II). CT-based AC, PET-based AC and uniform AC methods were compared. Results: The activity...

Predicting AC loss in practical superconductors

International Nuclear Information System (INIS)

Goemoery, F; Souc, J; Vojenciak, M; Seiler, E; Klincok, B; Ceballos, J M; Pardo, E; Sanchez, A; Navau, C; Farinon, S; Fabbricatore, P

2006-01-01

Recent progress in the development of methods used to predict AC loss in superconducting conductors is summarized. It is underlined that the loss is just one of the electromagnetic characteristics controlled by the time evolution of magnetic field and current distribution inside the conductor. Powerful methods for the simulation of magnetic flux penetration, like Brandt's method and the method of minimal magnetic energy variation, allow us to model the interaction of the conductor with an external magnetic field or a transport current, or with both of them. The case of a coincident action of AC field and AC transport current is of prime importance for practical applications. Numerical simulation methods allow us to expand the prediction range from simplified shapes like a (infinitely high) slab or (infinitely thin) strip to more realistic forms like strips with finite rectangular or elliptic cross-section. Another substantial feature of these methods is that the real composite structure containing an array of superconducting filaments can be taken into account. Also, the case of a ferromagnetic matrix can be considered, with the simulations showing a dramatic impact on the local field. In all these circumstances, it is possible to indicate how the AC loss can be reduced by a proper architecture of the composite. On the other hand, the multifilamentary arrangement brings about a presence of coupling currents and coupling loss. Simulation of this phenomenon requires 3D formulation with corresponding growth of the problem complexity and computation time

Scaling and universality of ac conduction in disordered solids

DEFF Research Database (Denmark)

Schrøder, Thomas; Dyre, Jeppe

2000-01-01

Recent scaling results for the ac conductivity of ionic glasses by Roling et al. [Phys. Rev. Lett. 78, 2160 (1997)] and Sidebottom [Phys. Rev. Lett. 82, 3653 (1999)] are discussed. We prove that Sidebottom's version of scaling is completely general. A new approximation to the universal ac conduct...... conductivity arising in the extreme disorder limit of the symmetric hopping model, the "diffusion cluster approximation," is presented and compared to computer simulations and experiments.......Recent scaling results for the ac conductivity of ionic glasses by Roling et al. [Phys. Rev. Lett. 78, 2160 (1997)] and Sidebottom [Phys. Rev. Lett. 82, 3653 (1999)] are discussed. We prove that Sidebottom's version of scaling is completely general. A new approximation to the universal ac...

Tomato leaf curl Kerala virus (ToLCKeV AC3 protein forms a higher order oligomer and enhances ATPase activity of replication initiator protein (Rep/AC1

Directory of Open Access Journals (Sweden)

Mukherjee Sunil K

2010-06-01

Full Text Available Abstract Background Geminiviruses are emerging plant viruses that infect a wide variety of vegetable crops, ornamental plants and cereal crops. They undergo recombination during co-infections by different species of geminiviruses and give rise to more virulent species. Antiviral strategies targeting a broad range of viruses necessitate a detailed understanding of the basic biology of the viruses. ToLCKeV, a virus prevalent in the tomato crop of Kerala state of India and a member of genus Begomovirus has been used as a model system in this study. Results AC3 is a geminiviral protein conserved across all the begomoviral species and is postulated to enhance viral DNA replication. In this work we have successfully expressed and purified the AC3 fusion proteins from E. coli. We demonstrated the higher order oligomerization of AC3 using sucrose gradient ultra-centrifugation and gel-filtration experiments. In addition we also established that ToLCKeV AC3 protein interacted with cognate AC1 protein and enhanced the AC1-mediated ATPase activity in vitro. Conclusions Highly hydrophobic viral protein AC3 can be purified as a fusion protein with either MBP or GST. The purification method of AC3 protein improves scope for the biochemical characterization of the viral protein. The enhancement of AC1-mediated ATPase activity might lead to increased viral DNA replication.

Cell cycle- and chaperone-mediated regulation of H3K56ac incorporation in yeast.

Science.gov (United States)

Kaplan, Tommy; Liu, Chih Long; Erkmann, Judith A; Holik, John; Grunstein, Michael; Kaufman, Paul D; Friedman, Nir; Rando, Oliver J

2008-11-01

Acetylation of histone H3 lysine 56 is a covalent modification best known as a mark of newly replicated chromatin, but it has also been linked to replication-independent histone replacement. Here, we measured H3K56ac levels at single-nucleosome resolution in asynchronously growing yeast cultures, as well as in yeast proceeding synchronously through the cell cycle. We developed a quantitative model of H3K56ac kinetics, which shows that H3K56ac is largely explained by the genomic replication timing and the turnover rate of each nucleosome, suggesting that cell cycle profiles of H3K56ac should reveal most first-time nucleosome incorporation events. However, since the deacetylases Hst3/4 prevent use of H3K56ac as a marker for histone deposition during M phase, we also directly measured M phase histone replacement rates. We report a global decrease in turnover rates during M phase and a further specific decrease in turnover at several early origins of replication, which switch from rapidly replaced in G1 phase to stably bound during M phase. Finally, by measuring H3 replacement in yeast deleted for the H3K56 acetyltransferase Rtt109 and its two co-chaperones Asf1 and Vps75, we find evidence that Rtt109 and Asf1 preferentially enhance histone replacement at rapidly replaced nucleosomes, whereas Vps75 appears to inhibit histone turnover at those loci. These results provide a broad perspective on histone replacement/incorporation throughout the cell cycle and suggest that H3K56 acetylation provides a positive-feedback loop by which replacement of a nucleosome enhances subsequent replacement at the same location.

Cell cycle- and chaperone-mediated regulation of H3K56ac incorporation in yeast.

Directory of Open Access Journals (Sweden)

Tommy Kaplan

2008-11-01

Full Text Available Acetylation of histone H3 lysine 56 is a covalent modification best known as a mark of newly replicated chromatin, but it has also been linked to replication-independent histone replacement. Here, we measured H3K56ac levels at single-nucleosome resolution in asynchronously growing yeast cultures, as well as in yeast proceeding synchronously through the cell cycle. We developed a quantitative model of H3K56ac kinetics, which shows that H3K56ac is largely explained by the genomic replication timing and the turnover rate of each nucleosome, suggesting that cell cycle profiles of H3K56ac should reveal most first-time nucleosome incorporation events. However, since the deacetylases Hst3/4 prevent use of H3K56ac as a marker for histone deposition during M phase, we also directly measured M phase histone replacement rates. We report a global decrease in turnover rates during M phase and a further specific decrease in turnover at several early origins of replication, which switch from rapidly replaced in G1 phase to stably bound during M phase. Finally, by measuring H3 replacement in yeast deleted for the H3K56 acetyltransferase Rtt109 and its two co-chaperones Asf1 and Vps75, we find evidence that Rtt109 and Asf1 preferentially enhance histone replacement at rapidly replaced nucleosomes, whereas Vps75 appears to inhibit histone turnover at those loci. These results provide a broad perspective on histone replacement/incorporation throughout the cell cycle and suggest that H3K56 acetylation provides a positive-feedback loop by which replacement of a nucleosome enhances subsequent replacement at the same location.

Preliminary study on AC superconducting machines

International Nuclear Information System (INIS)

Yamamoto, M.; Ishigohka, T.; Shimohka, T.; Mizukami, N.; Yamaguchi, M.

1988-01-01

This paper describes the issues involved in developing AC superconducting machines. In the first phase, as a preliminary experiment, a 4kVa AC superconducting coil which employs 100A class 50/60Hz superconductors is made and tested. And, in the second phase, as an extension of the 4kVa coil, a model superconducting transformer is made and examined. The transformer has a novel quench protection system with an auxiliary coil only in the low voltage side. The behavior of the overcurrent protection system is confirmed

21 CFR 880.5500 - AC-powered patient lift.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5500 AC-powered patient lift. (a) Identification. An AC-powered lift is an electrically powered device either fixed or mobile, used to lift and transport patients in the horizontal or other...

MAPK Signaling Pathway Alters Expression of Midgut ALP and ABCC Genes and Causes Resistance to Bacillus thuringiensis Cry1Ac Toxin in Diamondback Moth

Science.gov (United States)

Wu, Qingjun; Wang, Shaoli; Xie, Wen; Zhu, Xun; Baxter, Simon W.; Zhou, Xuguo; Jurat-Fuentes, Juan Luis; Zhang, Youjun

2015-01-01

Insecticidal crystal toxins derived from the soil bacterium Bacillus thuringiensis (Bt) are widely used as biopesticide sprays or expressed in transgenic crops to control insect pests. However, large-scale use of Bt has led to field-evolved resistance in several lepidopteran pests. Resistance to Bt Cry1Ac toxin in the diamondback moth, Plutella xylostella (L.), was previously mapped to a multigenic resistance locus (BtR-1). Here, we assembled the 3.15 Mb BtR-1 locus and found high-level resistance to Cry1Ac and Bt biopesticide in four independent P. xylostella strains were all associated with differential expression of a midgut membrane-bound alkaline phosphatase (ALP) outside this locus and a suite of ATP-binding cassette transporter subfamily C (ABCC) genes inside this locus. The interplay between these resistance genes is controlled by a previously uncharacterized trans-regulatory mechanism via the mitogen-activated protein kinase (MAPK) signaling pathway. Molecular, biochemical, and functional analyses have established ALP as a functional Cry1Ac receptor. Phenotypic association experiments revealed that the recessive Cry1Ac resistance was tightly linked to down-regulation of ALP, ABCC2 and ABCC3, whereas it was not linked to up-regulation of ABCC1. Silencing of ABCC2 and ABCC3 in susceptible larvae reduced their susceptibility to Cry1Ac but did not affect the expression of ALP, whereas suppression of MAP4K4, a constitutively transcriptionally-activated MAPK upstream gene within the BtR-1 locus, led to a transient recovery of gene expression thereby restoring the susceptibility in resistant larvae. These results highlight a crucial role for ALP and ABCC genes in field-evolved resistance to Cry1Ac and reveal a novel trans-regulatory signaling mechanism responsible for modulating the expression of these pivotal genes in P. xylostella. PMID:25875245

MAPK signaling pathway alters expression of midgut ALP and ABCC genes and causes resistance to Bacillus thuringiensis Cry1Ac toxin in diamondback moth.

Directory of Open Access Journals (Sweden)

Zhaojiang Guo

2015-04-01

Full Text Available Insecticidal crystal toxins derived from the soil bacterium Bacillus thuringiensis (Bt are widely used as biopesticide sprays or expressed in transgenic crops to control insect pests. However, large-scale use of Bt has led to field-evolved resistance in several lepidopteran pests. Resistance to Bt Cry1Ac toxin in the diamondback moth, Plutella xylostella (L., was previously mapped to a multigenic resistance locus (BtR-1. Here, we assembled the 3.15 Mb BtR-1 locus and found high-level resistance to Cry1Ac and Bt biopesticide in four independent P. xylostella strains were all associated with differential expression of a midgut membrane-bound alkaline phosphatase (ALP outside this locus and a suite of ATP-binding cassette transporter subfamily C (ABCC genes inside this locus. The interplay between these resistance genes is controlled by a previously uncharacterized trans-regulatory mechanism via the mitogen-activated protein kinase (MAPK signaling pathway. Molecular, biochemical, and functional analyses have established ALP as a functional Cry1Ac receptor. Phenotypic association experiments revealed that the recessive Cry1Ac resistance was tightly linked to down-regulation of ALP, ABCC2 and ABCC3, whereas it was not linked to up-regulation of ABCC1. Silencing of ABCC2 and ABCC3 in susceptible larvae reduced their susceptibility to Cry1Ac but did not affect the expression of ALP, whereas suppression of MAP4K4, a constitutively transcriptionally-activated MAPK upstream gene within the BtR-1 locus, led to a transient recovery of gene expression thereby restoring the susceptibility in resistant larvae. These results highlight a crucial role for ALP and ABCC genes in field-evolved resistance to Cry1Ac and reveal a novel trans-regulatory signaling mechanism responsible for modulating the expression of these pivotal genes in P. xylostella.

Biochemical and functional characterization of AcUFGT3a, a galactosyltransferase involved in anthocyanin biosynthesis in the red-fleshed kiwifruit (Actinidia chinensis).

Science.gov (United States)

Liu, Yanfei; Zhou, Bin; Qi, Yingwei; Liu, Cuihua; Liu, Zhande; Ren, Xiaolin

2018-04-01

Much of the diversity of anthocyanin pigmentation in plant tissues is due to the action of glycosyltransferases, which attach sugar moieties to the anthocyanin aglycone. This step can increase both their solubility and stability. We investigated the pigmentation of the outer and inner pericarps of developing fruits of the red-fleshed kiwifruit Actinidia chinensis cv. 'Hongyang'. The results show that the red color of the inner pericarp is due to anthocyanin. Based on expression analyses of structural genes, AcUFGT was shown to be the key gene involved in the anthocyanin biosynthetic pathway. Expression of AcUFGT in developing fruit paralleled changes in anthocyanin concentration. Thirteen putative UFGT genes, including different transcripts, were identified in the genome of 'Hongyang'. Among these, only the expression of AcUFGT3a was found to be highly consistent with anthocyanin accumulation. Fruit infiltrated with virus-induced gene silencing showed delayed red colorations, lower anthocyanin contents and lower expressions of AcUFGT3a. At the same time, transient overexpression of AcUFGT3a in both Actinidia arguta and green apple fruit resulted in higher anthocyanin contents and deeper red coloration. In vitro biochemical assays revealed that recombinant AcUFGT3a recognized only anthocyanidins as substrate but not flavonols. Also, UDP-galactose was used preferentially as the sugar donor. These results indicate AcUFGT3a is the key enzyme regulating anthocyanin accumulation in red-fleshed kiwifruit. © 2017 Scandinavian Plant Physiology Society.

Cooperative Frequency Control for Autonomous AC Microgrids

DEFF Research Database (Denmark)

Shafiee, Qobad; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

2015-01-01

Distributed secondary control strategies have been recently studied for frequency regulation in droop-based AC Microgrids. Unlike centralized secondary control, the distributed one might fail to provide frequency synchronization and proportional active power sharing simultaneously, due to having...... not require measuring the system frequency as compared to the other presented methods. An ac Microgrid with four sources is used to verify the performance of the proposed control methodology....

Diagnostics of the Fermilab Tevatron using an AC dipole

Energy Technology Data Exchange (ETDEWEB)

Miyamoto, Ryoichi [Univ. of Texas, Austin, TX (United States)

2008-08-01

The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f ~ 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.

Improved Design Methods for Robust Single- and Three-Phase ac-dc-ac Power Converters

DEFF Research Database (Denmark)

Qin, Zian

. The approaches for improving their performance, in terms of the voltage stress, efficiency, power density, cost, loss distribution, and temperature, will be studied. The structure of the thesis is as follows, Chapter 1 presents the introduction and motivation of the whole project as well as the background...... becomes a emerging challenge. Accordingly, installation of sustainable power generators like wind turbines and solar panels has experienced a large increase during the last decades. Meanwhile, power electronics converters, as interfaces in electrical system, are delivering approximately 80 % electricity...... back-to-back, and meanwhile improve the harmonics, control flexibility, and thermal distribution between the switches. Afterwards, active power decoupling methods for single-phase inverters or rectifiers that are similar to the single-phase ac-dc-ac converter, are studied in Chapter 4...

AC power flow importance measures considering multi-element failures

International Nuclear Information System (INIS)

Li, Jian; Dueñas-Osorio, Leonardo; Chen, Changkun; Shi, Congling

2017-01-01

Quantifying the criticality of individual components of power systems is essential for overall reliability and management. This paper proposes an AC-based power flow element importance measure, while considering multi-element failures. The measure relies on a proposed AC-based cascading failure model, which captures branch overflow, bus load shedding, and branch failures, via AC power flow and optimal power flow analyses. Taking the IEEE 30, 57 and 118-bus power systems as case studies, we find that N-3 analyses are sufficient to measure the importance of a bus or branch. It is observed that for a substation bus, its importance is statistically proportional to its power demand, but this trend is not observed for power plant buses. While comparing with other reliability, functionality, and topology-based importance measures popular today, we find that a DC power flow model, although better correlated with the benchmark AC model as a whole, still fails to locate some critical elements. This is due to the focus of DC-based models on real power that ignores reactive power. The proposed importance measure is aimed to inform decision makers about key components in complex systems, while improving cascading failure prevention, system backup setting, and overall resilience. - Highlights: • We propose a novel importance measure based on joint failures and AC power flow. • A cascading failure model considers both AC power flow and optimal power flow. • We find that N-3 analyses are sufficient to measure the importance of an element. • Power demand impacts the importance of substations but less so that of generators. • DC models fail to identify some key elements, despite correlating with AC models.

Systémový pohled na klub AC Sparta

OpenAIRE

Čečák, František

2015-01-01

Title: The system approach of the club AC Sparta Praha Objectives: Elaboration of financial analysis of the club AC Sparta Praha in season 2010/2011.Comparing the results of the financial analysis with the results of clubs FC Viktoria Plzeň and SK Slavia Praha. Prognosis of the club AC Sparta Praha until year 2020. Methods: In the elaboration of the analysis have been used these methods: vertical analysis, horizontal analysis and analysis of the financial ratios. For forecasting have been use...

Damaged DNA-binding protein down-regulates epigenetic mark H3K56Ac through histone deacetylase 1 and 2

Energy Technology Data Exchange (ETDEWEB)

Zhu, Qianzheng; Battu, Aruna; Ray, Alo; Wani, Gulzar; Qian, Jiang; He, Jinshan; Wang, Qi-en [Department of Radiology, The Ohio State University, Columbus, OH 43210 (United States); Wani, Altaf A., E-mail: wani.2@osu.edu [Department of Radiology, The Ohio State University, Columbus, OH 43210 (United States); Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH 43210 (United States); James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH 43210 (United States)

2015-06-15

Highlights: • HDAC1 and HDAC2 co-localize with UV radiation-induced DNA damage sites. • HDAC1 translocation to chromatin is dependent on DDB2 function. • HDAC1 and HDAC2 are involved in H3K56Ac deacetylation. • H3K56Ac deacetylation requires DDB1 and DDB2 but not XPA or XPC functions. • HDAC1/2 depletion decreases XPC ubiquitination and local γH2AX accumulation. - Abstract: Acetylated histone H3 lysine 56 (H3K56Ac) is one of the reversible histone post-translational modifications (PTMs) responsive to DNA damage. We previously described a biphasic decrease and increase of epigenetic mark H3K56Ac in response to ultraviolet radiation (UVR)-induced DNA damage. Here, we report a new function of UV damaged DNA-binding protein (DDB) in deacetylation of H3K56Ac through specific histone deacetylases (HDACs). We show that simultaneous depletion of HDAC1/2 compromises the deacetylation of H3K56Ac, while depletion of HDAC1 or HDAC2 alone has no effect on H3K56Ac. The H3K56Ac deacetylation does not require functional nucleotide excision repair (NER) factors XPA and XPC, but depends on the function of upstream factors DDB1 and DDB2. UVR enhances the association of DDB2 with HDAC1 and, enforced DDB2 expression leads to translocation of HDAC1 to UVR-damaged chromatin. HDAC1 and HDAC2 are recruited to UVR-induced DNA damage spots, which are visualized by anti-XPC immunofluorescence. Dual HDAC1/2 depletion decreases XPC ubiquitination, but does not affect the recruitment of DDB2 to DNA damage. By contrast, the local accumulation of γH2AX at UVR-induced DNA damage spots was compromised upon HDAC1 as well as dual HDAC1/2 depletions. Additionally, UVR-induced ATM activation decreased in H12899 cells expressing H3K56Ac-mimicing H3K56Q. These results revealed a novel role of DDB in H3K56Ac deacetylation during early step of NER and the existence of active functional cross-talk between DDB-mediated damage recognition and H3K56Ac deacetylation.

Ac system interruption analysis of an orthogonal-core type dc-ac converter. Koryu keito shadanji no chokko jishinkei dc-ac renkeiyo henkanki no dosa kaiseki

Energy Technology Data Exchange (ETDEWEB)

Sato, K; Ichinokura, O; Jinzenji, T [Tohoku Univ., Sendai (Japan). Faculty of Engineering; Tajima, K [Akita University, Akita (Japan). Mining College

1991-04-30

This paper reports on a numerical analysis of transient response of an orthogonal-core type dc-ac converter that takes place when the external ac system connected is cut off from it. A model of magnetic circuit of the orthogonal core is presented, which has magnetic inductances to represent effects produced by hysteresis that are connected in series with magnetic reluctances, thereby making it possible to divide each of primary and secondary winding current into magnetization current associated with magnetic reluctances and iron-loss current due to hysteresis. Moreover, a numerical model of the orthogonal core is derived from expressions for non-linear characteristics of these reluctances and inductances to make use of it for analyses employing the circuit simulator SPICE. Transient response of the present converter, namely time variation of both voltage and current in its every part, to the sudden change in condition that is caused by switching off the ac system connected to its secondary side is calculated, while applying square-wave voltage to its primary side. It is noted that calculated wave forms of both secondary winding current and open-circuit voltage are fairly in good agreement with those obtained by an experiment performed on the same condition. 4 refs., 9 figs., 1 tab.

Aragonite coating solutions (ACS) based on artificial seawater

Science.gov (United States)

Tas, A. Cuneyt

2015-03-01

Aragonite (CaCO3, calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca10(PO4)6(OH)2), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry.

Design and synthesis of {sup 225}Ac radioimmunopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

McDevitt, Michael R.; Ma, Dangshe; Simon, Jim; Frank, R. Keith; Scheinberg, David A. E-mail: d-scheinberg@ski.mskcc.org

2002-12-01

The alpha-particle-emitting radionuclides {sup 213}Bi, {sup 211}At, {sup 224}Ra are under investigation for the treatment of leukemias, gliomas, and ankylosing spondylitis, respectively. {sup 213}Bi and {sup 211}At were attached to monoclonal antibodies and used as targeted immunotherapeutic agents while unconjugated {sup 224}Ra chloride selectively seeks bone. {sup 225}Ac possesses favorable physical properties for radioimmunotherapy (10 d half-life and 4 net alpha particles), but has a history of unfavorable radiolabeling chemistry and poor metal-chelate stability. We selected functionalized derivatives of DOTA as the most promising to pursue from out of a group of potential {sup 225}Ac chelate compounds. A two-step synthetic process employing either MeO-DOTA-NCS or 2B-DOTA-NCS as the chelating moiety was developed to attach {sup 225}Ac to monoclonal antibodies. This method was tested using several different IgG systems. The chelation reaction yield in the first step was 93{+-}8% radiochemically pure (n=26). The second step yielded {sup 225}Ac-DOTA-IgG constructs that were 95{+-}5% radiochemically pure (n=27) and the mean percent immunoreactivity ranged from 25% to 81%, depending on the antibody used. This process has yielded several potential novel targeted {sup 225}Ac-labeled immunotherapeutic agents that may now be evaluated in appropriate model systems and ultimately in humans.

Influence of transgenic rice expressing a fused Cry1Ab/1Ac protein on frogs in paddy fields.

Science.gov (United States)

Wang, Jia-Mei; Chen, Xiu-Ping; Liang, Yu-Yong; Zhu, Hao-Jun; Ding, Jia-Tong; Peng, Yu-Fa

2014-11-01

As genetic engineering in plants is increasingly used to control agricultural pests, it is important to determine whether such transgenic plants adversely affect non-target organisms within and around cultivated fields. The cry1Ab/1Ac fusion gene from Bacillus thuringiensis (Bt) has insecticidal activity and has been introduced into rice line Minghui 63 (MH63). We evaluated the effect of transgenic cry1Ab/1Ac rice (Huahui 1, HH1) on paddy frogs by comparing HH1 and MH63 rice paddies with and without pesticide treatment. The density of tadpoles in rice fields was surveyed at regular intervals, and Cry1Ab/1Ac protein levels were determined in tissues of tadpoles and froglets collected from the paddy fields. In addition, Rana nigromaculata froglets were raised in purse nets placed within these experimental plots. The survival, body weight, feeding habits, and histological characteristics of the digestive tract of these froglets were analyzed. We found that the tadpole density was significantly decreased immediately after pesticide application, and the weight of R. nigromaculata froglets of pesticide groups was significantly reduced compared with no pesticide treatment, but we found no differences between Bt and non-Bt rice groups. Moreover, no Cry1Ab/1Ac protein was detected in tissue samples collected from 192 tadpoles and froglets representing all four experimental groups. In addition, R. nigromaculata froglets raised in purse seines fed primarily on stem borer and non-target insects, and showed no obvious abnormality in the microstructure of their digestive tracts. Based on these results, we conclude that cultivation of transgenic cry1Ab/1Ac rice does not adversely affect paddy frogs.

ac propulsion system for an electric vehicle

Science.gov (United States)

Geppert, S.

1980-01-01

It is pointed out that dc drives will be the logical choice for current production electric vehicles (EV). However, by the mid-80's, there is a good chance that the price and reliability of suitable high-power semiconductors will allow for a competitive ac system. The driving force behind the ac approach is the induction motor, which has specific advantages relative to a dc shunt or series traction motor. These advantages would be an important factor in the case of a vehicle for which low maintenance characteristics are of primary importance. A description of an EV ac propulsion system is provided, taking into account the logic controller, the inverter, the motor, and a two-speed transmission-differential-axle assembly. The main barrier to the employment of the considered propulsion system in EV is not any technical problem, but inverter transistor cost.

Systémový pohled na klub AC Sparta

OpenAIRE

Čečák, František

2014-01-01

Title: The system approach of the club AC Sparta Praha Aim of the paper: Elaboration of financial analysis of the club AC Sparta Praha in season 2010/2011.Comparing the results of the financial analysis with the results of clubs FC Viktoria Plzeň and SK Slavia Praha. Prognosis of the club AC Sparta Praha until year 2020. Methods: In the elaboration of the analysis have been used these methods: vertical analysis, horizontal analysis and analysis of the financial ratios. For forecasting have be...

Advanced reliability improvement of AC-modules (ARIA)

International Nuclear Information System (INIS)

Rooij, P.; Real, M.; Moschella, U.; Sample, T.; Kardolus, M.

2001-09-01

The AC-module is a relatively new development in PV-system technology and offers significant advantages over conventional PV-systems with a central inverter : e.g. increased modularity, ease of installation and freedom of system design. The Netherlands and Switzerland have a leading position in the field of AC-modules, both in terms of technology and of commercial and large-scale application. An obstacle towards large-scale market introduction of AC-modules is that the reliability and operational lifetime of AC-modules and the integrated inverters in particular are not yet proven. Despite the advantages, no module-integrated inverter has yet achieved large scale introduction. The AC-modules will lower the barrier towards market penetration. But due to the great interest in the new AC-module technology there is the risk of introducing a not fully proven product. This may damage the image of PV-systems. To speed up the development and to improve the reliability, research institutes and PV-industry will address the aspects of reliability and operational lifetime of AC-modules. From field experiences we learn that in general the inverter is still the weakest point in PV-systems. The lifetime of inverters is an important factor on reliability. Some authors are indicating a lifetime of 1.5 years, whereas the field experiences in Germany and Switzerland have shown that for central inverter systems, an availability of 97% has been achieved in the last years. From this point of view it is highly desirable that the operational lifetime and reliability of PV-inverters and especially AC-modules is demonstrated/improved to make large scale use of PV a success. Module Integrated Inverters will most likely be used in modules in the power range between 100 and 300 Watt DC-power. These are modules with more than 100 cells in series, assuming that the module inverter will benefit from the higher voltage. Hot-spot is the phenomenon that can occur when one or more cells of a string

Mapa acústico parcial de Benetusser

OpenAIRE

MORILLA CASTELLANOS, EMILIO

2012-01-01

Se establece el mapa de ruido del municipio de Benetússer para evaluar y conocer su exposición al ruido ambiental y así poder dar cumplimiento a la Directiva Europea sobre Gestión y Evaluación de Ruido Ambiental (2002/49/CE) y a la Ley nacional 37/2003 del Ruido. Los mapas estratégicos de ruido nos aportan la información fundamental para diagnosticar la situación acústica y para la gestión del ruido ambiental. Morilla Castellanos, E. (2012). Mapa acústico parcial de Benetusser. http://h...

Six switches solution for single-phase AC/DC/AC converter with capability of second-order power mitigation in DC-link capacitor

DEFF Research Database (Denmark)

Liu, Xiong; Wang, Peng; Loh, Poh Chiang

2011-01-01

This paper proposes an approach for DC-link second-order harmonic power cancellation in single-phase AC/DC/AC converter with reduced number of switches. The proposed six-switch converter has two bridges with three switches in each of them, where the middle switch in each bridge is shared by the A...

AC conductivity of a quantum Hall line junction

International Nuclear Information System (INIS)

Agarwal, Amit; Sen, Diptiman

2009-01-01

We present a microscopic model for calculating the AC conductivity of a finite length line junction made up of two counter- or co-propagating single mode quantum Hall edges with possibly different filling fractions. The effect of density-density interactions and a local tunneling conductance (σ) between the two edges is considered. Assuming that σ is independent of the frequency ω, we derive expressions for the AC conductivity as a function of ω, the length of the line junction and other parameters of the system. We reproduce the results of Sen and Agarwal (2008 Phys. Rev. B 78 085430) in the DC limit (ω→0), and generalize those results for an interacting system. As a function of ω, the AC conductivity shows significant oscillations if σ is small; the oscillations become less prominent as σ increases. A renormalization group analysis shows that the system may be in a metallic or an insulating phase depending on the strength of the interactions. We discuss the experimental implications of this for the behavior of the AC conductivity at low temperatures.

Mass of AC Andromedae

International Nuclear Information System (INIS)

King, D.S.; Cox, A.N.; Hodson, S.W.

1975-01-01

Calculations indicate that AC Andromedae is population I rather than population II. A mass and radius for this star are calculated using a new set of opacities for the Kippenhahn Ia mixture. It is concluded that the mass is too high for an ordinary RR Lyrae star. (BJG)

ac18 is not essential for the propagation of Autographa californica multiple nucleopolyhedrovirus

International Nuclear Information System (INIS)

Wang Yanjie; Wu Wenbi; Li Zhaofei; Yuan Meijin; Feng Guozhong; Yu Qian; Yang Kai; Pang Yi

2007-01-01

orf18 (ac18) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a highly conserved gene in lepidopteran nucleopolyhedroviruses, but its function remains unknown. In this study, an ac18 knockout AcMNPV bacmid was generated to determine the role of ac18 in baculovirus life cycle. After transfection of Sf-9 cells, the ac18-null mutant showed similar infection pattern to the parent virus and the ac18 repair virus with respect to the production of infectious budded virus, occlusion bodies, or the formation of nucleocapsids as visualized by electron microscopy. The deletion mutant did not reduce AcMNPV infectivity for Trichoplusia ni in LD 50 bioassay; however, it did take 24 h longer for deleted mutant to kill T. ni larvae than wild-type virus in LT 50 bioassay. Our results demonstrate that ac18 is not essential for viral propagation both in vitro and in vivo, but it may play a role in efficient virus infection in T. ni larvae

De novo synthesis and functional analysis of the phosphatase-encoding gene acI-B of uncultured Actinobacteria from Lake Stechlin (NE Germany).

Science.gov (United States)

Srivastava, Abhishek; McMahon, Katherine D; Stepanauskas, Ramunas; Grossart, Hans-Peter

2015-12-01

The National Center for Biotechnology Information [http://www.ncbi.nlm.nih.gov/guide/taxonomy/] database enlists more than 15,500 bacterial species. But this also includes a plethora of uncultured bacterial representations. Owing to their metabolism, they directly influence biogeochemical cycles, which underscores the the important status of bacteria on our planet. To study the function of a gene from an uncultured bacterium, we have undertaken a de novo gene synthesis approach. Actinobacteria of the acI-B subcluster are important but yet uncultured members of the bacterioplankton in temperate lakes of the northern hemisphere such as oligotrophic Lake Stechlin (NE Germany). This lake is relatively poor in phosphate (P) and harbors on average ~1.3 x 10 6 bacterial cells/ml, whereby Actinobacteria of the ac-I lineage can contribute to almost half of the entire bacterial community depending on seasonal variability. Single cell genome analysis of Actinobacterium SCGC AB141-P03, a member of the acI-B tribe in Lake Stechlin has revealed several phosphate-metabolizing genes. The genome of acI-B Actinobacteria indicates potential to degrade polyphosphate compound. To test for this genetic potential, we targeted the exoP-annotated gene potentially encoding polyphosphatase and synthesized it artificially to examine its biochemical role. Heterologous overexpression of the gene in Escherichia coli and protein purification revealed phosphatase activity. Comparative genome analysis suggested that homologs of this gene should be also present in other Actinobacteria of the acI lineages. This strategic retention of specialized genes in their genome provides a metabolic advantage over other members of the aquatic food web in a P-limited ecosystem. [Int Microbiol 2016; 19(1):39-47]. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

Detection of Genetic Modification 'ac2' in Potato Foodstuffs

Directory of Open Access Journals (Sweden)

Petr Kralik

2009-01-01

Full Text Available The genetic modification 'ac2' is based on the insertion and expression of ac2 gene, originally found in seeds of amaranth (Amaranthus caudatus, into the genome of potatoes (Solanum tuberosum. The purpose of the present study is to develop a PCR method for the detection of the mentioned genetically modified potatoes in various foodstuffs. The method was used to test twenty different potato-based products; none of them was positive for the genetic modification 'ac2'. The European Union legislation requires labelling of products made of or containing more than 0.9 % of genetically modified organisms. The genetic modification 'ac2' is not allowed on the European Union market. For that reason it is suitable to have detection methods, not only for the approved genetic modifications, but also for the 'unknown' ones, which could still occur in foodstuffs.

Arthroscopically Assisted Reconstruction of Acute Acromioclavicular Joint Dislocations: Anatomic AC Ligament Reconstruction With Protective Internal Bracing—The “AC-RecoBridge” Technique

Science.gov (United States)

Izadpanah, Kaywan; Jaeger, Martin; Ogon, Peter; Südkamp, Norbert P.; Maier, Dirk

2015-01-01

An arthroscopically assisted technique for the treatment of acute acromioclavicular joint dislocations is presented. This pathology-based procedure aims to achieve anatomic healing of both the acromioclavicular ligament complex (ACLC) and the coracoclavicular ligaments. First, the acromioclavicular joint is reduced anatomically under macroscopic and radiologic control and temporarily transfixed with a K-wire. A single-channel technique using 2 suture tapes provides secure coracoclavicular stabilization. The key step of the procedure consists of the anatomic repair of the ACLC (“AC-Reco”). Basically, we have observed 4 patterns of injury: clavicular-sided, acromial-sided, oblique, and midportion tears. Direct and/or transosseous ACLC repair is performed accordingly. Then, an X-configured acromioclavicular suture tape cerclage (“AC-Bridge”) is applied under arthroscopic assistance to limit horizontal clavicular translation to a physiological extent. The AC-Bridge follows the principle of internal bracing and protects healing of the ACLC repair. The AC-Bridge is tightened on top of the repair, creating an additional suture-bridge effect and promoting anatomic ACLC healing. We refer to this combined technique of anatomic ACLC repair and protective internal bracing as the “AC-RecoBridge.” A detailed stepwise description of the surgical technique, including indications, technical pearls and pitfalls, and potential complications, is given. PMID:26052493

Ammonia treated Mo/AC catalysts for CO hydrogenation with ...

Indian Academy of Sciences (India)

SHARIF F ZAMAN

the influence of acid treated AC as a support with K-Ni-. Mo active ... K-Ni-Mo/AC catalyst was more selective to oxygenates. (>40% ... mineral impurities (K, Si, Sn and Fe) <1%. ...... edge technical support with thanks Science and Technology.

Estimation of the Thurstonian model for the 2-AC protocol

DEFF Research Database (Denmark)

Christensen, Rune Haubo Bojesen; Lee, Hye-Seong; Brockhoff, Per B.

2012-01-01

. This relationship makes it possible to extract estimates and standard errors of δ and τ from general statistical software, and furthermore, it makes it possible to combine standard regression modelling with the Thurstonian model for the 2-AC protocol. A model for replicated 2-AC data is proposed using cumulative......The 2-AC protocol is a 2-AFC protocol with a “no-difference” option and is technically identical to the paired preference test with a “no-preference” option. The Thurstonian model for the 2-AC protocol is parameterized by δ and a decision parameter τ, the estimates of which can be obtained...... by fairly simple well-known methods. In this paper we describe how standard errors of the parameters can be obtained and how exact power computations can be performed. We also show how the Thurstonian model for the 2-AC protocol is closely related to a statistical model known as a cumulative probit model...

System and method for determining stator winding resistance in an AC motor

Science.gov (United States)

Lu, Bin [Kenosha, WI; Habetler, Thomas G [Snellville, GA; Zhang, Pinjia [Atlanta, GA; Theisen, Peter J [West Bend, WI

2011-05-31

A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

Lamin A/C might be involved in the EMT signalling pathway.

Science.gov (United States)

Zuo, Lingkun; Zhao, Huanying; Yang, Ronghui; Wang, Liyong; Ma, Hui; Xu, Xiaoxue; Zhou, Ping; Kong, Lu

2018-07-15

We have previously reported a heterogeneous expression pattern of the nuclear membrane protein lamin A/C in low- and high-Gleason score (GS) prostate cancer (PC) tissues, and we have now found that this change is not associated with LMNA mutations. This expression pattern appears to be similar to the process of epithelial to mesenchymal transition (EMT) or to that of mesenchymal to epithelial transition (MET). The role of lamin A/C in EMT or MET in PC remains unclear. Therefore, we first investigated the expression levels of and the associations between lamin A/C and several common EMT markers, such as E-cadherin, N-cadherin, β-catenin, snail, slug and vimentin in PC tissues with different GS values and in different cell lines with varying invasion abilities. Our results suggest that lamin A/C might constitute a type of epithelial marker that better signifies EMT and MET in PC tissue, since a decrease in lamin A/C expression in GS 4 + 5 cases is likely associated with the EMT process, while the re-expression of lamin A/C in GS 5 + 4 cases is likely linked with MET. The detailed GS better exhibited the changes in lamin A/C and the EMT markers examined. Lamin A/C overexpression or knockdown had an impact on EMT biomarkers in a cell model by direct regulation of β-catenin. Hence, we suggest that lamin A/C might serve as a reliable epithelial biomarker for the distinction of PC cell differentiation and might also be a fundamental factor in the occurrence of EMT or MET in PC. Copyright © 2018. Published by Elsevier B.V.

Autonomous Operation of Hybrid Microgrid With AC and DC Subgrids

DEFF Research Database (Denmark)

Chiang Loh, Poh; Li, Ding; Kang Chai, Yi

2013-01-01

sources distributed throughout the two types of subgrids, which is certainly tougher than previous efforts developed for only ac or dc microgrid. This wider scope of control has not yet been investigated, and would certainly rely on the coordinated operation of dc sources, ac sources, and interlinking...... converters. Suitable control and normalization schemes are now developed for controlling them with the overall hybrid microgrid performance already verified in simulation and experiment.......This paper investigates on power-sharing issues of an autonomous hybrid microgrid. Unlike existing microgrids which are purely ac, the hybrid microgrid studied here comprises dc and ac subgrids interconnected by power electronic interfaces. The main challenge here is to manage power flows among all...

Brain Oscillatory and Hemodynamic Activity in a Bimanual Coordination Task Following Transcranial Alternating Current Stimulation (tACS: A Combined EEG-fNIRS Study

Directory of Open Access Journals (Sweden)

Alisa Berger

2018-04-01

Full Text Available Motor control is associated with synchronized oscillatory activity at alpha (8–12 Hz and beta (12–30 Hz frequencies in a cerebello-thalamo-cortical network. Previous studies demonstrated that transcranial alternating current stimulation (tACS is capable of entraining ongoing oscillatory activity while also modulating motor control. However, the modulatory effects of tACS on both motor control and its underlying electro- and neurophysiological mechanisms remain ambiguous. Thus, the purpose of this study was to contribute to gathering neurophysiological knowledge regarding tACS effects by investigating the after-effects of 10 Hz tACS and 20 Hz tACS at parietal brain areas on bimanual coordination and its concurrent oscillatory and hemodynamic activity. Twenty-four right-handed healthy volunteers (12 females aged between 18 and 30 (M = 22.35 ± 3.62 participated in the study and performed a coordination task requiring bimanual movements. Concurrent to bimanual motor training, participants received either 10 Hz tACS, 20 Hz tACS or a sham stimulation over the parietal cortex (at P3/P4 electrode positions for 20 min via small gel electrodes (3,14 cm2 Ag/AgCl, amperage = 1 mA. Before and three time-points after tACS (immediately, 30 min and 1 day, bimanual coordination performance was assessed. Oscillatory activities were measured by electroencephalography (EEG and hemodynamic changes were examined using functional near-infrared spectroscopy (fNIRS. Improvements of bimanual coordination performance were not differently between groups, thus, no tACS-specific effect on bimanual coordination performance emerged. However, physiological measures during the task revealed significant increases in parietal alpha activity immediately following 10 Hz tACS and 20 Hz tACS which were accompanied by significant decreases of Hboxy concentration in the right hemispheric motor cortex compared to the sham group. Based on the physiological responses, we conclude that

Brain Oscillatory and Hemodynamic Activity in a Bimanual Coordination Task Following Transcranial Alternating Current Stimulation (tACS): A Combined EEG-fNIRS Study.

Science.gov (United States)

Berger, Alisa; Pixa, Nils H; Steinberg, Fabian; Doppelmayr, Michael

2018-01-01

Motor control is associated with synchronized oscillatory activity at alpha (8-12 Hz) and beta (12-30 Hz) frequencies in a cerebello-thalamo-cortical network. Previous studies demonstrated that transcranial alternating current stimulation (tACS) is capable of entraining ongoing oscillatory activity while also modulating motor control. However, the modulatory effects of tACS on both motor control and its underlying electro- and neurophysiological mechanisms remain ambiguous. Thus, the purpose of this study was to contribute to gathering neurophysiological knowledge regarding tACS effects by investigating the after-effects of 10 Hz tACS and 20 Hz tACS at parietal brain areas on bimanual coordination and its concurrent oscillatory and hemodynamic activity. Twenty-four right-handed healthy volunteers (12 females) aged between 18 and 30 ( M = 22.35 ± 3.62) participated in the study and performed a coordination task requiring bimanual movements. Concurrent to bimanual motor training, participants received either 10 Hz tACS, 20 Hz tACS or a sham stimulation over the parietal cortex (at P3/P4 electrode positions) for 20 min via small gel electrodes (3,14 cm 2 Ag/AgCl, amperage = 1 mA). Before and three time-points after tACS (immediately, 30 min and 1 day), bimanual coordination performance was assessed. Oscillatory activities were measured by electroencephalography (EEG) and hemodynamic changes were examined using functional near-infrared spectroscopy (fNIRS). Improvements of bimanual coordination performance were not differently between groups, thus, no tACS-specific effect on bimanual coordination performance emerged. However, physiological measures during the task revealed significant increases in parietal alpha activity immediately following 10 Hz tACS and 20 Hz tACS which were accompanied by significant decreases of Hboxy concentration in the right hemispheric motor cortex compared to the sham group. Based on the physiological responses, we conclude that tACS

Regulation of P450-mediated permethrin resistance in Culex quinquefasciatus by the GPCR/Gαs/AC/cAMP/PKA signaling cascade.

Science.gov (United States)

Li, Ting; Liu, Nannan

2017-12-01

This study explores the role of G-protein-coupled receptor-intracellular signaling in the development of P450-mediated insecticide resistance in mosquitoes, Culex quinquefasciatus , focusing on the essential function of the GPCRs and their downstream effectors of Gs alpha subunit protein (Gαs) and adenylyl cyclase (ACs) in P450-mediated insecticide resistance of Culex mosquitoes. Our RNAi-mediated functional study showed that knockdown of Gαs caused the decreased expression of the downstream effectors of ACs and PKAs in the GPCR signaling pathway and resistance P450 genes, whereas knockdown of ACs decreased the expression of PKAs and resistance P450 genes. Knockdown of either Gαs or ACs resulted in an increased susceptibility of mosquitoes to permethrin. These results add significantly to our understanding of the molecular basis of resistance P450 gene regulation through GPCR/Gαs/AC/cAMP-PKA signaling pathways in the insecticide resistance of mosquitoes. The temporal and spatial dynamic analyses of GPCRs, Gαs, ACs, PKAs, and P450s in two insecticide resistant mosquito strains revealed that all the GPCR signaling pathway components tested, namely GPCRs, Gαs, ACs and PKAs, were most highly expressed in the brain for both resistant strains, suggesting the role played by these genes in signaling transduction and regulation. The resistance P450 genes were mainly expressed in the brain, midgut and malpighian tubules (MTs), suggesting their critical function in the central nervous system and importance for detoxification. The temporal dynamics analysis for the gene expression showed a diverse expression profile during mosquito development, indicating their initially functional importance in response to exposure to insecticides during their life stages.

The Effects of Theta and Gamma tACS on Working Memory and Electrophysiology

Directory of Open Access Journals (Sweden)

Anja Pahor

2018-01-01

Full Text Available A single blind sham-controlled study was conducted to explore the effects of theta and gamma transcranial alternating current stimulation (tACS on offline performance on working memory tasks. In order to systematically investigate how specific parameters of tACS affect working memory, we manipulated the frequency of stimulation (theta frequency vs. gamma frequency, the type of task (n-back vs. change detection task and the content of the tasks (verbal vs. figural stimuli. A repeated measures design was used that consisted of three sessions: theta tACS, gamma tACS and sham tACS. In total, four experiments were conducted which differed only with respect to placement of tACS electrodes (bilateral frontal, bilateral parietal, left fronto-parietal and right-fronto parietal. Healthy female students (N = 72 were randomly assigned to one of these groups, hence we were able to assess the efficacy of theta and gamma tACS applied over different brain areas, contrasted against sham stimulation. The pre-post/sham resting electroencephalogram (EEG analysis showed that theta tACS significantly affected theta amplitude, whereas gamma tACS had no significant effect on EEG amplitude in any of the frequency bands of interest. Gamma tACS did not significantly affect working memory performance compared to sham, and theta tACS led to inconsistent changes in performance on the n-back tasks. Active theta tACS significantly affected P3 amplitude and latency during performance on the n-back tasks in the bilateral parietal and right-fronto parietal protocols.

AC power losses in Bi-2223/Ag HTS tapes

International Nuclear Information System (INIS)

Savvides, N.; Reilly, D.; Mueller, K.-H.; Herrmann, J.

1998-01-01

Full text: We report measurements at 77 K of the transport ac losses of Bi-2223/Ag composite tapes. The investigated tapes vary from single filament to multifilament construction and include both conventional tapes and other conductor shapes with twisted filaments. The self-field ac losses were determined at 77 K and 60 Hz as a function of ac current amplitude (0 - 100 A). We observe different behaviour among tapes depending on their quality and strain history. For 'good' virgin tapes the experimental data are well described by the Norris equations for the dependence of power loss P on the amplitude I m of the transport current. The data of good monofilament tapes are fitted to the Norris equation P ∼ I m n for an elliptical cross section (ie. n = 3) and the data of good multifilament tapes are fitted to the Norris equation for a rectangular strip (ie. n = 4). Many specimens, however, show a range of behaviour with lower values of n. Based on our work on the effect of strain on the dc transport properties of tapes, we carried out detailed investigations of the effect of controlled applied bend strain on the ac loss. Our results show that irreversible damage to superconducting filaments (ie. cracks) cause the ac loss to rise and n to decrease with increasing strain. In addition, applied strains much greater than the irreversible strain limit cause the ac loss to increase by several orders of magnitude and become ohmic in character with n = 2. Theoretical work is in progress to model the observed behaviour

Nuclear structure of {sup 231}Ac

Energy Technology Data Exchange (ETDEWEB)

Boutami, R. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); Borge, M.J.G. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain)], E-mail: borge@iem.cfmac.csic.es; Mach, H. [Department of Radiation Sciences, ISV, Uppsala University, SE-751 21 Uppsala (Sweden); Kurcewicz, W. [Department of Physics, University of Warsaw, Pl-00 681 Warsaw (Poland); Fraile, L.M. [Departamento Fisica Atomica, Molecular y Nuclear, Facultad CC. Fisicas, Universidad Complutense, E-28040 Madrid (Spain); ISOLDE, PH Department, CERN, CH-1211 Geneva 23 (Switzerland); Gulda, K. [Department of Physics, University of Warsaw, Pl-00 681 Warsaw (Poland); Aas, A.J. [Department of Chemistry, University of Oslo, PO Box 1033, Blindern, N-0315 Oslo (Norway); Garcia-Raffi, L.M. [Instituto de Fisica Corpuscular, CSIC - Universidad de Valencia, Apdo. 22805, E-46071 Valencia (Spain); Lovhoiden, G. [Department of Physics, University of Oslo, PO Box 1048, Blindern, N-0316 Oslo (Norway); Martinez, T.; Rubio, B.; Tain, J.L. [Instituto de Fisica Corpuscular, CSIC - Universidad de Valencia, Apdo. 22805, E-46071 Valencia (Spain); Tengblad, O. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); ISOLDE, PH Department, CERN, CH-1211 Geneva 23 (Switzerland)

2008-10-15

The low-energy structure of {sup 231}Ac has been investigated by means of {gamma} ray spectroscopy following the {beta}{sup -} decay of {sup 231}Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a MINI-ORANGE electron spectrometer. The decay scheme of {sup 231}Ra {yields}{sup 231}Ac has been constructed for the first time. The Advanced Time Delayed {beta}{gamma}{gamma}(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus.

Statistical time lags in ac discharges

International Nuclear Information System (INIS)

Sobota, A; Kanters, J H M; Van Veldhuizen, E M; Haverlag, M; Manders, F

2011-01-01

The paper presents statistical time lags measured for breakdown events in near-atmospheric pressure argon and xenon. Ac voltage at 100, 400 and 800 kHz was used to drive the breakdown processes, and the voltage amplitude slope was varied between 10 and 1280 V ms -1 . The values obtained for the statistical time lags are roughly between 1 and 150 ms. It is shown that the statistical time lags in ac-driven discharges follow the same general trends as the discharges driven by voltage of monotonic slope. In addition, the validity of the Cobine-Easton expression is tested at an alternating voltage form.

Statistical time lags in ac discharges

Energy Technology Data Exchange (ETDEWEB)

Sobota, A; Kanters, J H M; Van Veldhuizen, E M; Haverlag, M [Eindhoven University of Technology, Department of Applied Physics, Postbus 513, 5600MB Eindhoven (Netherlands); Manders, F, E-mail: a.sobota@tue.nl [Philips Lighting, LightLabs, Mathildelaan 1, 5600JM Eindhoven (Netherlands)

2011-04-06

The paper presents statistical time lags measured for breakdown events in near-atmospheric pressure argon and xenon. Ac voltage at 100, 400 and 800 kHz was used to drive the breakdown processes, and the voltage amplitude slope was varied between 10 and 1280 V ms{sup -1}. The values obtained for the statistical time lags are roughly between 1 and 150 ms. It is shown that the statistical time lags in ac-driven discharges follow the same general trends as the discharges driven by voltage of monotonic slope. In addition, the validity of the Cobine-Easton expression is tested at an alternating voltage form.

Study on AC loss measurements of HTS power cable for standardizing

Science.gov (United States)

Mukoyama, Shinichi; Amemiya, Naoyuki; Watanabe, Kazuo; Iijima, Yasuhiro; Mido, Nobuhiro; Masuda, Takao; Morimura, Toshiya; Oya, Masayoshi; Nakano, Tetsutaro; Yamamoto, Kiyoshi

2017-09-01

High-temperature superconducting power cables (HTS cables) have been developed for more than 20 years. In addition of the cable developments, the test methods of the HTS cables have been discussed and proposed in many laboratories and companies. Recently the test methods of the HTS cables is required to standardize and to common in the world. CIGRE made the working group (B1-31) for the discussion of the test methods of the HTS cables as a power cable, and published the recommendation of the test method. Additionally, IEC TC20 submitted the New Work Item Proposal (NP) based on the recommendation of CIGRE this year, IEC TC20 and IEC TC90 started the standardization work on Testing of HTS AC cables. However, the individual test method that used to measure a performance of HTS cables hasn’t been established as world’s common methods. The AC loss is one of the most important properties to disseminate low loss and economical efficient HTS cables in the world. We regard to establish the method of the AC loss measurements in rational and in high accuracy. Japan is at a leading position in the AC loss study, because Japanese researchers have studied on the AC loss technically and scientifically, and also developed the effective technologies for the AC loss reduction. The JP domestic commission of TC90 made a working team to discussion the methods of the AC loss measurements for aiming an international standard finally. This paper reports about the AC loss measurement of two type of the HTS conductors, such as a HTS conductor without a HTS shield and a HTS conductor with a HTS shield. The AC loss measurement method is suggested by the electrical method..

a.c. conductance study of polycrystal C60

International Nuclear Information System (INIS)

Yan Feng; Wang Yening; Huang Yineng; Gu Min; Zhang Qingming; Shen Huimin

1995-01-01

The a.c. (1 60 polycrystal (grain size 30 nm) has been studied from 100 to 350 K. Below 150 K, the a.c. conductance is nearly proportional to the temperature and frequency. This is proposed to be due to the hopping of localized states around the Fermi level. Above 200 K, the a.c. conductance exhibits a rapid increase with temperature, and shows a thermally activated behaviour with an activation energy of 0.389 eV below a certain temperature and 0.104 eV above it. A frequency dependent conductance at a fixed temperature is also obtained with a power law σ similar ω s (s∼0.8). For a sample of normal grain size, we have measured a peak near 250 K and a much smaller conductance. These results indicate that the defective na ture of our sample (small grain size, disorder or impurities) plays an important role for the transport properties. The existence of nanocrystals in the sample may give rise to localized states and improve its a.c. conductance. The two activation energies can be attributed to the coexistence of the crystalline and amorphous phases of C 60 . ((orig.))

Study of the AC machines winding having fractional q

Science.gov (United States)

Bespalov, V. Y.; Sidorov, A. O.

2018-02-01

The winding schemes with a fractional numbers of slots per pole and phase q have been known and used for a long time. However, in the literature on the low-noise machines design there are not recommended to use. Nevertheless, fractional q windings have been realized in many applications of special AC electrical machines, allowing to improve their performance, including vibroacoustic one. This paper deals with harmonic analysis of windings having integer and fractional q in permanent magnet synchronous motors, a comparison of their characteristics is performed, frequencies of subharmonics are revealed. Optimal winding pitch design is found giving reduce the amplitudes of subharmonics. Distribution factors for subharmonics, fractional and high-order harmonics are calculated, results analysis is represented, allowing for giving recommendations how to calculate distribution factors for different harmonics when q is fractional.

Control of Power Converters in AC Microgrids

DEFF Research Database (Denmark)

Rocabert, Joan; Luna, Alvaro; Blaabjerg, Frede

2012-01-01

The enabling of ac microgrids in distribution networks allows delivering distributed power and providing grid support services during regular operation of the grid, as well as powering isolated islands in case of faults and contingencies, thus increasing the performance and reliability of the ele......The enabling of ac microgrids in distribution networks allows delivering distributed power and providing grid support services during regular operation of the grid, as well as powering isolated islands in case of faults and contingencies, thus increasing the performance and reliability...

Droop-free Distributed Control for AC Microgrids

DEFF Research Database (Denmark)

Nasirian, Vahidreza; Shafiee, Qobad; Guerrero, Josep M.

2016-01-01

A cooperative distributed secondary/primary control paradigm for AC microgrids is proposed. This solution replaces the centralized secondary control and the primary-level droop mechanism of each inverter with three separate regulators: voltage, reactive power, and active power regulators. A sparse...... guidelines are provided. Steady-state performance analysis shows that the proposed controller can accurately handle the global voltage regulation and proportional load sharing. An AC microgrid prototype is set up, where the controller performance, plug-and-play capability, and resiliency to the failure...

Effect of AC electric fields on the stabilization of premixed bunsen flames

KAUST Repository

Kim, Minkuk

2011-01-01

The stabilization characteristics of laminar premixed bunsen flames have been investigated experimentally for stoichiometric methane-air mixture by applying AC voltage to the nozzle with the single-electrode configuration. The detachment velocity either at blowoff or partial-detachment has been measured by varying the applied voltage and frequency of AC. The result showed that the detachment velocity increased with the applied AC electric fields, such that the flame could be nozzle-attached even over five times of the blowoff velocity without having electric fields. There existed four distinct regimes depending on applied AC voltage and frequency. In the low voltage regime, the threshold condition of AC electric fields was identified, below which the effect of electric fields on the detachment velocity is minimal. In the moderate voltage regime, the flame base oscillated with the frequency synchronized to AC frequency and the detachment velocity increased linearly with the applied AC voltage and nonlinearly with the frequency. In the high voltage regime, two different sub-regimes depending on AC frequency were observed. For relatively low frequency, the flame base oscillated with the applied AC frequency together with the half frequency and the variation of the detachment velocity was insensitive to the applied voltage. For relatively high frequency, the stabilization of the flame was significantly affected by the generation of streamers and the detachment velocity decreased with the applied voltage. © 2010 Published by Elsevier Inc. on behalf of The Combustion Institute. All rights reserved.

Objectives and status of development of AC600

International Nuclear Information System (INIS)

Zhao Chengkun

1997-01-01

AC600 is a medium power capability nuclear power station of next generation, which is developed based on world nuclear power improving tendency, requirements of custom with considering China situation and technical foundation. Its main technical characteristics are as following: advanced core and passive safety system, double loop standard design and international popular equipment. Meanwhile, it a simplification of present system, using advanced control room and pattern construction thus developed the operation reliability of nuclear power station, lower construction and operating cost. In order to accelerate the development of next generation advanced reactor, cooperating with Westinghouse Electric Corporation, the joint economic technical research has been established. Based on AC600, the CAP600 is developed on further improving safety and reliability, economical and electric network adoption of AC600

Introduction of hvdc transmission into a predominantly ac network

Energy Technology Data Exchange (ETDEWEB)

Casson, W; Last, F H; Huddart, K W

1966-02-01

Methods for reinforcing the supply network, including systems employing dc links, without introducing a new primary network are briefly described. The arrangement for dc links is outlined and the application to an existing ac system is considered. The economics of ac and dc for reinforcement schemes are briefly mentioned.

21 CFR 880.5510 - Non-AC-powered patient lift.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5510 Non-AC-powered patient lift. (a) Identification. A non-AC-powered patient lift is a hydraulic, battery, or mechanically powered device, either fixed or mobile, used to lift and transport a...

Comparative evaluation of Bis(thiosemicarbazone)- Biotin and Met-ac-TE3A for tumor imaging

Science.gov (United States)

Singh, Sweta; Tiwari, Anjani K.; Varshney, Raunak; Mathur, R.; Shukla, Gauri; Bag, N.; Singh, B.; Mishra, Anil K.

2016-01-01

2,2‧,2″-(11-(2-((4-mercapto-1-methoxy-1-oxobutan-2-yl)amino)-2-oxoethyl)-1,4,8,11-tetraaza cyclotetradecane-1,4,8-triyl)triacetic acid, Met-ac-TE3A and (E)-N-methyl-2-((E)-3-(2-(2-(5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanoyl)hydrazinecarbono-thioyl)hydrazonobutan-2-ylidene)hydrazinecarbothioamide, Bis(thiosemicarbazone)- Biotin were synthesized and evaluated for imaging application. The pharmacokinetics of these ligands were determined by tracer methods. In vitro human serum stability of 99mTc Met-ac-TE3A/99mTc Bis(thiosemicarbazone)-Biotin after 24 h was found to be 96.5% and 97.0% respectively. Blood kinetics of both ligands in normal rabbits showed biphasic clearance pattern. Ex vivo biodistribution study revealed significant initial tumor uptake and high tumor/muscles ratio which is a pre-requisite condition for a ligand to work as SPECT-radiopharmaceutical for tumor imaging.

Effect of the valence electron concentration on the bulk modulus and chemical bonding in Ta2AC and Zr2AC (A=Al, Si, and P)

International Nuclear Information System (INIS)

Schneider, Jochen M.; Music, Denis; Sun Zhimei

2005-01-01

We have studied the effect of the valence electron concentration, on the bulk modulus and the chemical bonding in Ta 2 AC and Zr 2 AC (A=Al, Si, and P) by means of ab initio calculations. Our equilibrium volume and the hexagonal ratio (c/a) agree well (within 2.7% and 1.2%, respectively) with previously published experimental data for Ta 2 AlC. The bulk moduli of both Ta 2 AC and Zr 2 AC increase as Al is substituted with Si and P by 13.1% and 20.1%, respectively. This can be understood since the substitution is associated with an increased valence electron concentration, resulting in band filling and an extensive increase in cohesion

Low ac loss geometries in YBCO coated conductors and impact on conductor stability

Energy Technology Data Exchange (ETDEWEB)

Duckworth, Robert C [ORNL; List III, Frederick Alyious [ORNL; Paranthaman, Mariappan Parans [ORNL; Rupich, M. W. [American Superconductor Corporation, Westborough, MA; Zhang, W. [American Superconductor Corporation, Westborough, MA; Xie, Y. Y. [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York

2007-01-01

Reduction of ac losses in applied ac fields can be accomplished through either the creation of filaments and bridging in YBCO coated conductors or an assembly of narrow width YBCO tapes. The ac losses for each of these geometries were measured at 77 K in perpendicular ac fields up to 100 mT. While ac loss reduction was achieved with YBCO filaments created through laser scribing and inkjet deposition, the assembly of stacked YBCO conductor provides an alternative method of ac loss reduction. When compared to a 4-mm wide YBCO coated conductor with a critical current of 60 A, the ac loss in a stack of 2-mm wide YBCO coated conductors with a similar total critical current was reduced. While the reduction in ac loss in a 2-mm wide stack coincided with the reduction in the engineering current density of the conductor, further reduction of ac loss was obtained through the splicing of the 2-mm wide tapes with low resistance solders. To better determine the practicality of these methods from a stability point of view, a numerical analysis was carried out to determine the influence of bridging and splicing on stability of a YBCO coated conductor for both liquid nitrogen-cooled and conduction cooled geometries.

Measurement of ac electrical characteristics of SSC dipole magnets at Brookhaven

International Nuclear Information System (INIS)

Smedley, K.

1992-04-01

The SSC collider is designed to have circumference of 87 km. The superconducting magnets along the collider ring are grouped into ten sectors. Each sector, a string of average length of 8.7 km,m is powered by one power source located near the center of the sector. Because of the alternating-current (ac) electrical characteristics of the magnets, the power supply ripple currents and transients form a time and space distribution in the magnet string which affects particle motions. Additionally, since the power supply load is a magnet string, the current regulation loop design is highly dependent upon the ac electrical characteristics of the magnets. A means is needed to accurately determine the ac electrical characteristics of the superconducting magnets. The ac characteristics of magnets will be used to predict the ripple distribution of the long string of superconducting magnets. Magnet ac characteristics can also provide necessary information for the regulation loop design. This paper presents a method for measuring the ac characteristics of superconducting magnets. Two collider dipole magnets, one superconducting and one at room temperature, were tested at Brookhaven National Lab

The effect of surface grain reversal on the AC losses of sintered Nd–Fe–B permanent magnets

International Nuclear Information System (INIS)

Moore, Martina; Roth, Stefan; Gebert, Annett; Schultz, Ludwig; Gutfleisch, Oliver

2015-01-01

Sintered Nd–Fe–B magnets are exposed to AC magnetic fields in many applications, e.g. in permanent magnet electric motors. We have measured the AC losses of sintered Nd–Fe–B magnets in a closed circuit arrangement using AC fields with root mean square-values up to 80 mT (peak amplitude 113 mT) over the frequency range 50 to 1000 Hz. Two magnet grades with different dysprosium content were investigated. Around the remanence point the low grade material (1.7 wt% Dy) showed significant hysteresis losses; whereas the losses in the high grade material (8.9 wt% Dy) were dominated by classical eddy currents. Kerr microscopy images revealed that the hysteresis losses measured for the low grade magnet can be mainly ascribed to grains at the sample surface with multiple domains. This was further confirmed when the high grade material was subsequently exposed to DC and AC magnetic fields. Here a larger number of surface grains with multiple domains are also present once the step in the demagnetization curve attributed to the surface grain reversal is reached and a rise in the measured hysteresis losses is evident. If in the low grade material the operating point is slightly offset from the remanence point, such that zero field is not bypassed, its AC losses can also be fairly well described with classical eddy current theory. - Highlights: • The eddy current losses of sintered Nd–Fe–B magnets were measured. • Field amplitudes up to 113 mT over the frequency range 50 to 1000 Hz were applied. • The Nd–Fe–B magnets showed significant hysteresis losses at low amplitudes (∼100 mT). • The source of such hysteresis losses in sintered Nd–Fe–B magnets was identified. • Two magnet grades with different dysprosium content were investigated

The effect of surface grain reversal on the AC losses of sintered Nd–Fe–B permanent magnets

Energy Technology Data Exchange (ETDEWEB)

Moore, Martina, E-mail: m.moore@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, 01171 Dresden (Germany); Roth, Stefan; Gebert, Annett [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, 01171 Dresden (Germany); Schultz, Ludwig [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, 01171 Dresden (Germany); TU Dresden, Institute for Materials Science, 01062 Dresden (Germany); Gutfleisch, Oliver [TU Darmstadt, Department of Materials Science, Alarich-Weiß-Str. 16, 64287 Darmstadt (Germany); Fraunhofer Project Group for Materials Recycling and Resource Strategies IWKS, 63457 Hanau (Germany)

2015-02-01

Sintered Nd–Fe–B magnets are exposed to AC magnetic fields in many applications, e.g. in permanent magnet electric motors. We have measured the AC losses of sintered Nd–Fe–B magnets in a closed circuit arrangement using AC fields with root mean square-values up to 80 mT (peak amplitude 113 mT) over the frequency range 50 to 1000 Hz. Two magnet grades with different dysprosium content were investigated. Around the remanence point the low grade material (1.7 wt% Dy) showed significant hysteresis losses; whereas the losses in the high grade material (8.9 wt% Dy) were dominated by classical eddy currents. Kerr microscopy images revealed that the hysteresis losses measured for the low grade magnet can be mainly ascribed to grains at the sample surface with multiple domains. This was further confirmed when the high grade material was subsequently exposed to DC and AC magnetic fields. Here a larger number of surface grains with multiple domains are also present once the step in the demagnetization curve attributed to the surface grain reversal is reached and a rise in the measured hysteresis losses is evident. If in the low grade material the operating point is slightly offset from the remanence point, such that zero field is not bypassed, its AC losses can also be fairly well described with classical eddy current theory. - Highlights: • The eddy current losses of sintered Nd–Fe–B magnets were measured. • Field amplitudes up to 113 mT over the frequency range 50 to 1000 Hz were applied. • The Nd–Fe–B magnets showed significant hysteresis losses at low amplitudes (∼100 mT). • The source of such hysteresis losses in sintered Nd–Fe–B magnets was identified. • Two magnet grades with different dysprosium content were investigated.

Flame spread over inclined electrical wires with AC electric fields

KAUST Repository

Lim, Seung J.; Park, Sun H.; Park, Jeong; Fujita, Osamu; Keel, Sang I.; Chung, Suk-Ho

2017-01-01

Flame spread over polyethylene-insulated electrical wires was studied experimentally with applied alternating current (AC) by varying the inclination angle (θ), applied voltage (VAC), and frequency (fAC). For the baseline case with no electric field

Spectroscopy of nuclei 215Fr and 219 Ac: a contribution to the study of the nuclear structure of light actinides

International Nuclear Information System (INIS)

Khazrouni, S.

1985-06-01

Using α-particle and γ-ray spectroscopy, it has been possible to establish the high spin pattern in 215 Fr and propose a decay scheme up to I π = (47/2 + ) containing six isomeric states. These results are interpreted using the recent version of the deformed Woods-Saxon model and the Strutinsky normalisation technique. A similar study in 219 Ac has revealed the existence of two quasi-bands each formed of states of alternating parity and connected by strong E1 transitions. This data for 219 Ac fits better with the stable octupole deformation model, mainly because of the high-spin parity doublets observed for the first time, than with the α-cluster model [fr

DC and AC biasing of a transition edge sensor microcalorimeter

International Nuclear Information System (INIS)

Cunningham, M.F.; Ullom, J.N.; Miyazaki, T.; Drury, O.; Loshak, A.; Berg, M.L. van den; Labov, S.E.

2002-01-01

We are developing AC-biased transition edge sensor (TES) microcalorimeters for use in large arrays with frequency-domain multiplexing. Using DC bias, we have achieved a resolution of 17 eV FWHM at 2.6 keV with a decay time of 90 μs and an effective detector diameter of 300 μm. We have successfully measured thermal pulses with a TES microcalorimeter operated with an AC bias. We present here preliminary results from a single pixel detector operated under DC and AC bias conditions

Coordination Control Strategy for AC/DC Hybrid Microgrids in Stand-Alone Mode

Directory of Open Access Journals (Sweden)

Dwi Riana Aryani

2016-06-01

Full Text Available Interest in DC microgrids is rapidly increasing along with the improvement of DC power technology because of its advantages. To support the integration process of DC microgrids with the existing AC utility grids, the form of hybrid AC/DC microgrids is considered for higher power conversion efficiency, lower component cost and better power quality. In the system, AC and DC portions are connected through interlink bidirectional AC/DC converters (IC with a proper control system and power management. In the stand-alone operation mode of AC/DC hybrid microgrids, the control of power injection through the IC is crucial in order to maintain the system security. This paper mainly deals with a coordination control strategy of IC and a battery energy storage system (BESS converter under stand-alone operation. A coordinated control strategy for the IC, which considers the state of charge (SOC level of BESS and the load shedding scheme as the last resort, is proposed to obtain better power sharing between AC and DC subgrids. The scheme will be tested with a hybrid AC/DC microgrid, using the tool of the PSCAD/EMTDC software.

Aragonite coating solutions (ACS) based on artificial seawater

International Nuclear Information System (INIS)

Tas, A. Cuneyt

2015-01-01

Graphical abstract: - Highlights: • Developed completely inorganic solutions for the deposition of monolayers of aragonite spherules (or ooids). • Solutions mimicked the artificial seawater. • Biomimetic crystallization was performed at the tropical sea surface temperature of 30 °C. - Abstract: Aragonite (CaCO 3 , calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry

Aragonite coating solutions (ACS) based on artificial seawater

Energy Technology Data Exchange (ETDEWEB)

Tas, A. Cuneyt, E-mail: c_tas@hotmail.com

2015-03-01

Graphical abstract: - Highlights: • Developed completely inorganic solutions for the deposition of monolayers of aragonite spherules (or ooids). • Solutions mimicked the artificial seawater. • Biomimetic crystallization was performed at the tropical sea surface temperature of 30 °C. - Abstract: Aragonite (CaCO{sub 3}, calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry.

Genomic Survey, Characterization, and Expression Profile Analysis of the SBP Genes in Pineapple (Ananas comosus L.).

Science.gov (United States)

Ali, Hina; Liu, Yanhui; Azam, Syed Muhammad; Rahman, Zia Ur; Priyadarshani, S V G N; Li, Weimin; Huang, Xinyu; Hu, Bingyan; Xiong, Junjie; Ali, Umair; Qin, Yuan

2017-01-01

Gene expression is regulated by transcription factors, which play many significant developmental processes. SQUAMOSA promoter-binding proteins (SBP) perform a variety of regulatory functions in leaf, flower, and fruit development, plant architecture, and sporogenesis. 16 SBP genes were identified in pineapple and were divided into four groups on basis of phylogenetic analysis. Five paralogs in pineapple for SBP genes were identified with Ka/Ks ratio varied from 0.20 for AcSBP14 and AcSBP15 to 0.36 for AcSBP6 and AcSBP16 , respectively. 16 SBP genes were located on 12 chromosomes out of 25 pineapple chromosomes with highly conserved protein sequence structures. The isoionic points of SBP ranged from 6.05 to 9.57, while molecular weight varied from 22.7 to 121.9 kD. Expression profiles of SBP genes revealed that AcSBP7 and AcSBP15 (leaf), AcSBP13 , AcSBP12 , AcSBP8 , AcSBP16 , AcSBP9 , and AcSBP11 (sepal), AcSBP6 , AcSBP4 , and AcSBP10 (stamen), AcSBP14 , AcSBP1 , and AcSBP5 (fruit) while the rest of genes showed low expression in studied tissues. Four genes, that is, AcSBP11 , AcSBP6 , AcSBP4 , and AcSBP12 , were highly expressed at 4°C, while AcSBP16 were upregulated at 45°C. RNA-Seq was validated through qRT-PCR for some genes. Salt stress-induced expression of two genes, that is, AcSBP7 and AcSBP14 , while in drought stress, AcSBP12 and AcSBP15 were highly expressed. Our study lays a foundation for further gene function and expression studies of SBP genes in pineapple.

Ac conductivity and relaxation mechanism in Ba{sub 0.9}Sr{sub 0.1}TiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Singh, A K; Barik, Subrat K [Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302 (India); Choudhary, R N.P. , [Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302 (India); Mahapatra, P K [Department of Physics, Vidyasagar University, Midnapore 721 102 (India)

2009-06-24

The ac conductivity and relaxation mechanism in Ba{sub 0.9}Sr{sub 0.1}TiO{sub 3} ceramics have been investigated systematically. A high-temperature solid-state reaction technique was used to synthesize the compound. The formation of the compound was checked by an X-ray diffraction (XRD) technique. The dielectric permittivity and the loss tangent of the sample were measured in a frequency range from 1 kHz to 1 MHz at different temperatures (30-500 deg. C). A study on dielectric properties reveals the electrical relaxation phenomenon occurs in the material. The activation energy was calculated from the temperature variation of dc conductivity. Studies of frequency and temperature dependence of ac conductivity of the compound suggest that conduction process in the material is thermally activated.

The Cryogenic Anti-Coincidence detector for ATHENA X-IFU: pulse analysis of the AC-S7 single pixel prototype

Science.gov (United States)

D'Andrea, M.; Argan, A.; Lotti, S.; Macculi, C.; Piro, L.; Biasotti, M.; Corsini, D.; Gatti, F.; Torrioli, G.

2016-07-01

The ATHENA observatory is the second large-class mission in ESA Cosmic Vision 2015-2025, with a launch foreseen in 2028 towards the L2 orbit. The mission addresses the science theme "The Hot and Energetic Universe", by coupling a high-performance X-ray Telescope with two complementary focal-plane instruments. One of these is the X-ray Integral Field Unit (X-IFU): it is a TES based kilo-pixel order array able to provide spatially resolved high-resolution spectroscopy (2.5 eV at 6 keV) over a 5 arcmin FoV. The X-IFU sensitivity is degraded by the particles background expected at L2 orbit, which is induced by primary protons of both galactic and solar origin, and mostly by secondary electrons. To reduce the background level and enable the mission science goals, a Cryogenic Anticoincidence (CryoAC) detector is placed address the final design of the CryoAC. It will verify some representative requirements at single-pixel level, especially the detector operation at 50 mK thermal bath and the threshold energy at 20 keV. To reach the final DM design we have developed and tested the AC-S7 prototype, with 1 cm2 absorber area sensed by 65 Ir TESes. Here we will discuss the pulse analysis of this detector, which has been illuminated by the 60 keV line from a 241Am source. First, we will present the analysis performed to investigate pulses timings and spectrum, and to disentangle the athermal component of the pulses from the thermal one. Furthermore, we will show the application to our dataset of an alternative method of pulse processing, based upon Principal Component Analysis (PCA). This kind of analysis allow us to recover better energy spectra than achievable with traditional methods, improving the evaluation of the detector threshold energy, a fundamental parameter characterizing the CryoAC particle rejection efficiency.

Development of low AC loss windings for superconducting traction transformer

International Nuclear Information System (INIS)

Kamijo, H; Hata, H; Fukumoto, Y; Tomioka, A; Bohno, T; Yamada, H; Ayai, N; Yamasaki, K; Kato, T; Iwakuma, M; Funaki, K

2010-01-01

We have been developing a light weight and high efficiency superconducting traction transformer for railway rolling stock. We designed and fabricated a prototype superconducting traction transformer of a floor-mount type for Shinkansen rolling stock in 2004. We performed the type-test, the system-test, and the vibration-test. Consequently, we could verify that the transformer satisfied the requirement almost exactly as initially planned. However, there have been raised some problems to be solved to put superconducting traction transformer into practical use such that AC loss of the superconducting tape must be lower and the capacity of the refrigerator must be larger. Especially it is the most important to reduce the AC loss of superconducting windings for lightweight and high efficiency. The AC loss must be reduced near the theoretical value of superconducting tape with multifilament. In this study, we fabricated and evaluated the Bi2223 tapes as introduced various measures to reduce the AC loss. We confirmed that the AC loss of the narrow type of Bi2223 tapes with twist of filaments is lower, and we fabricated windings of this tape for use in superconducting traction transformer.

Hybrid AC-High Voltage DC Grid Stability and Controls

Science.gov (United States)

Yu, Jicheng

The growth of energy demands in recent years has been increasing faster than the expansion of transmission facility construction. This tendency cooperating with the continuous investing on the renewable energy resources drives the research, development, and construction of HVDC projects to create a more reliable, affordable, and environmentally friendly power grid. Constructing the hybrid AC-HVDC grid is a significant move in the development of the HVDC techniques; the form of dc system is evolving from the point-to-point stand-alone dc links to the embedded HVDC system and the multi-terminal HVDC (MTDC) system. The MTDC is a solution for the renewable energy interconnections, and the MTDC grids can improve the power system reliability, flexibility in economic dispatches, and converter/cable utilizing efficiencies. The dissertation reviews the HVDC technologies, discusses the stability issues regarding the ac and HVDC connections, proposes a novel power oscillation control strategy to improve system stability, and develops a nonlinear voltage droop control strategy for the MTDC grid. To verify the effectiveness the proposed power oscillation control strategy, a long distance paralleled AC-HVDC transmission test system is employed. Based on the PSCAD/EMTDC platform simulation results, the proposed power oscillation control strategy can improve the system dynamic performance and attenuate the power oscillations effectively. To validate the nonlinear voltage droop control strategy, three droop controls schemes are designed according to the proposed nonlinear voltage droop control design procedures. These control schemes are tested in a hybrid AC-MTDC system. The hybrid AC-MTDC system, which is first proposed in this dissertation, consists of two ac grids, two wind farms and a five-terminal HVDC grid connecting them. Simulation studies are performed in the PSCAD/EMTDC platform. According to the simulation results, all the three design schemes have their unique salient

AC Calorimetric Design for Dynamic of Biological Materials

OpenAIRE

Shigeo Imaizumi

2006-01-01

We developed a new AC calorimeter for the measurement of dynamic specific heat capacity in liquids, including aqueous suspensions of biological materials. This method has several advantages. The first is that a high-resolution measurement of heat capacity, inmillidegrees, can be performed as a function of temperature, even with a very small sample. Therefore, AC calorimeter is a powerful tool to study critical behavior a tphase transition in biological materials. The second advantage is that ...

Study of dielectric relaxation and AC conductivity of InP:S single crystal

Science.gov (United States)

El-Nahass, M. M.; Ali, H. A. M.; El-Shazly, E. A.

2012-07-01

The dielectric relaxation and AC conductivity of InP:S single crystal were studied in the frequency range from 100 to 5.25 × 105 Hz and in the temperature range from 296 to 455 K. The dependence of the dielectric constant (ɛ1) and the dielectric loss (ɛ2) on both frequency and temperature was investigated. Since no peak was observed on the dielectric loss, we used a method based on the electric modulus to evaluate the activation energy of the dielectric relaxation. Scaling of the electric modulus spectra showed that the charge transport dynamics is independent of temperature. The AC conductivity (σAC) was found to obey the power law: Aωs. Analysis of the AC conductivity data and the frequency exponent showed that the correlated barrier hopping (CBH) model is the dominant mechanism for the AC conduction. The variation of AC conductivity with temperature at different frequencies showed that σAC is a thermally activated process.

Self-field AC losses in Bi-2223 superconducting tapes

International Nuclear Information System (INIS)

Mueller, K. H.; Leslie, K.E.

1996-01-01

Full text: The self-field AC loss in Bi-2223 silver sheathed tapes for AC currents of up to 100 A was measured at 77 K and frequencies of 60 Hz and 600 Hz using a lock-in amplifier. The frequency dependence indicated a purely hysteretic loss which can be well described in terms of the critical state model for a flat superconducting strip. The only parameter needed to predict the self-field AC loss is the critical current of the critical state. Because the loss voltage is extremely small compared with the inductive voltage, a very high accuracy of the lock-in amplifier phase setting is required. Unlike in loss measurements on cylindrical superconducting samples, in the case of the tape the measuring circuit leads have to be brought out from the surface forming a loop where the changing magnetic field induces an additional voltage. Only if the loop formed by the leads at the voltage tabs is large enough will the apparent power dissipation approach the real AC loss associated with the length of the sample probed

O Melos e Harmonia Acústica (1988 de César Guerra-Peixe, Koellreutter e Hindemith: similaridades e princípios básicos The Melos e Harmonia Acústica (1988 of César Guerra-Peixe, Koellreutter and Hindemith: basic principles and similarities

Directory of Open Access Journals (Sweden)

Ernesto Hartmann

2013-06-01

Full Text Available O Melos e Harmonia Acústica de César GUERRA-PEIXE (1988 apresenta um compêndio da atividade didática deste compositor expresso em forma de apostila. O presente trabalho busca traçar as possíveis influências comparando-o ao Caderno de Estudos com Koellreutter do próprio GUERRA-PEIXE (1944 e ao The Craft of Musical Composition de Paul HINDEMITH (1937, visando compreender melhor os pressupostos técnicos e teóricos.The Melos e Harmonia Acústica by César GUERRA-PEIXE (1988, presented a survey of the didactical activity of this composer expressed in a textbook form. This research attempts to trace possible influences, comparing it to The Craft of Musical Composition by Paul HINDEMITH (1937 and Caderno de Estudos com Koellreutter by GUERRA-PEIXE (1944 in order to better understand the technical and theoretical approaches embodied in it.

Laboratory testing in the emergency department: an Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC and Academy of Emergency Medicine and Care (AcEMC consensus report

Directory of Open Access Journals (Sweden)

Giuseppe Lippi

2017-04-01

Full Text Available The mainstay of patient-oriented laboratory testing in emergency settings entails selecting number and type of tests according to valid criteria of appropriateness. Since the pattern of urgent tests requesting is variable across different institutions, we designed a joined survey between the Academy of Emergency Medicine and Care (AcEMC and the Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC for reaching tentative consensus about the most informative diagnostic tests in emergency settings. A survey, containing the most commonly performed urgent laboratory tests and the relative clinical indications, was disseminated to eight relevant members of AcEMC and eight relevant members of SIBioC. All contributors were asked to provide numerical scores for the different laboratory parameters, where 1 indicated strongly recommended, 2 recommended in specific circumstances, and 3 strongly discouraged. The mean results of the survey were presented as the mean of responders’ values, and the parameters were finally classified as strongly recommended (mean value, 1.0-1.5, somehow recommended (mean value, 1.5-2.0, discouraged (mean value, 2.0-2.5 and strongly discouraged (mean value, 2.5-3.0. The results of the survey allowed defining a hierarchy of priority, wherein 24 tests were strongly recommended. The use of 5 common tests was instead strongly discouraged. For 16 additional parameters in the list, the consensus ranged between somehow recommended and discouraged. We hope that results presented in this joint AcEMC-SIBioC consensus document may help harmonizing panel of tests and requesting patters in emergency setting, at least at a national level.

AC susceptibility of thin Pb films in intermediate and mixed state

Energy Technology Data Exchange (ETDEWEB)

Janu, Zdenek, E-mail: janu@fzu.cz [Institute of Physics of the AS CR, v.v.i., Na Slovance 2, CZ-182 21 Prague 8 (Czech Republic); Svindrych, Zdenek [Institute of Physics of the AS CR, v.v.i., Na Slovance 2, CZ-182 21 Prague 8 (Czech Republic); Trunecek, Otakar [Charles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 3, CZ-121 16 Prague 2 (Czech Republic); Kus, Peter; Plecenik, Andrej [Komenius University in Bratislava, Faculty of Mathematics, Physics, and Informatics, Mlynska dolina, 842 48 Bratislava 4 (Slovakia)

2011-12-15

Thickness dependent transition in AC susceptibility between intermediate and mixed state in type-I superconducting films. The temperature induced crossover between reversible and irreversible behavior was observed in the thicker film. The temperature dependence of the AC susceptibility in mixed state follows prediction of model based on Bean critical state. The temperature dependence of the harmonics of the complex AC susceptibility in the intermediate state is explained. Thin films of type I superconductors of a thickness comparable or less than a flux penetration length behave like type II superconductors in a mixed state. With decreasing film thickness normal domains carrying a magnetic flux get smaller with smaller number of flux quanta per domain and finally transform into single quantum flux lines, i.e. quantum vortices similar to those found in type II superconductors. We give an evidence of this behavior from the measurements of the nonlinear response of a total magnetic moment to an applied AC magnetic field, directly from the temperature dependence of an AC susceptibility.

Numerical and theoretical evaluations of AC losses for single and infinite numbers of superconductor strips with direct and alternating transport currents in external AC magnetic field

Science.gov (United States)

Kajikawa, K.; Funaki, K.; Shikimachi, K.; Hirano, N.; Nagaya, S.

2010-11-01

AC losses in a superconductor strip are numerically evaluated by means of a finite element method formulated with a current vector potential. The expressions of AC losses in an infinite slab that corresponds to a simple model of infinitely stacked strips are also derived theoretically. It is assumed that the voltage-current characteristics of the superconductors are represented by Bean's critical state model. The typical operation pattern of a Superconducting Magnetic Energy Storage (SMES) coil with direct and alternating transport currents in an external AC magnetic field is taken into account as the electromagnetic environment for both the single strip and the infinite slab. By using the obtained results of AC losses, the influences of the transport currents on the total losses are discussed quantitatively.

Whole tissue AC susceptibility after superparamagnetic iron oxide contrast agent administration in a rat model

International Nuclear Information System (INIS)

Lazaro, Francisco Jose; Gutierrez, Lucia; Rosa Abadia, Ana; Soledad Romero, Maria; Lopez, Antonio; Jesus Munoz, Maria

2007-01-01

A magnetic AC susceptibility characterisation of rat tissues after intravenous administration of superparamagnetic iron oxide (Endorem ( R)), at the same dose as established for Magnetic Resonance Imaging (MRI) contrast enhancement in humans, has been carried out. The measurements reveal the presence of the contrast agent as well as that of physiological ferritin in liver and spleen while no traces have been magnetically detected in heart and kidney. This preliminary work opens suggestive possibilities for future biodistribution studies of any type of magnetic carriers

Flexible AC transmission systems: the state of the art

Energy Technology Data Exchange (ETDEWEB)

Edris, Abdel-Aty [Electric Power Research Inst., Palo Alto, CA (United States). Electric Systems Division

1994-12-31

Flexible AC transmission systems (FACTS) is a concept promoting the use of power electronic controllers to enhance the controllability and usable capacity of AC transmission. This paper presents the state of the art of FACTS and the status of the current projects for the application of the FACTS controllers in transmission systems. (author) 8 refs., 8 figs.

Operation of AC Adapters Visualized Using Light-Emitting Diodes

Science.gov (United States)

Regester, Jeffrey

2016-01-01

A bridge rectifier is a diamond-shaped configuration of diodes that serves to convert alternating current(AC) into direct current (DC). In our world of AC outlets and DC electronics, they are ubiquitous. Of course, most bridge rectifiers are built with regular diodes, not the light-emitting variety, because LEDs have a number of disadvantages. For…

A.C. losses in current-carrying superconductors

International Nuclear Information System (INIS)

Reuver, J.L. de.

1985-01-01

The feasibility of superconductors for alternating current use depends on successful reduction of losses. Moreover, the demand for large field amplitudes is a stimulation for investigating the nature of a.c. losses (e.g. in the set of poloidal coils in a TOKAMAK). In this thesis, measurements are performed at a.c. superconductivity. Attention is given to various external field conditions as well as to self-field instability. Measurements are performed on different types of wires. A type of wire is searched for with both low losses and a good stabilization under self-field conditions. (G.J.P.)

A Hubble Space Telescope Survey of the Disk Cluster Population of M31. II. Advanced Camera for Surveys Pointings

Science.gov (United States)

Krienke, O. K.; Hodge, P. W.

2008-01-01

This paper reports on a survey of star clusters in M31 based on archival images from the Hubble Space Telescope. Paper I reported results from images obtained with the Wide Field Planetary Camera 2 (WFPC2) and this paper reports results from the Advanced Camera for Surveys (ACS). The ACS survey has yielded a total of 339 star clusters, 52 of which—mostly globular clusters—were found to have been cataloged previously. As for the previous survey, the luminosity function of the clusters drops steeply for absolute magnitudes fainter than MV = -3 the implied cluster mass function has a turnover for masses less than a few hundred solar masses. The color-integrated magnitude diagram of clusters shows three significant features: (1) a group of very red, luminous objects: the globular clusters, (2) a wide range in color for the fainter clusters, representing a considerable range in age and reddening, and (3) a maximum density of clusters centered approximately at V = 21, B - V = 0.30, V - I = 0.50, where there are intermediate-age, intermediate-mass clusters with ages close to 500 million years and masses of about 2000 solar masses. We give a brief qualitative interpretation of the distribution of clusters in the CMDs in terms of their formation and destruction rates. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for research in astronomy, Inc., under NASA contract NAS 5-26555.

Logistics Reduction: Advanced Clothing System (ACS)

Data.gov (United States)

National Aeronautics and Space Administration — The goal of the Advanced Exploration System (AES) Logistics Reduction (LR) project's Advanced Clothing System (ACS) is to use advanced commercial off-the-shelf...

The Difficult Evolution of Intensive Cardiac Care Units: An Overview of the BLITZ-3 Registry and Other Italian Surveys.

Science.gov (United States)

Casella, Gianni; Zagnoni, Silvia; Fradella, Giuseppe; Scorcu, Giampaolo; Chinaglia, Alessandra; Pavesi, Pier Camillo; Di Pasquale, Giuseppe; Oltrona Visconti, Luigi

2017-01-01

Coronary care units, initially developed to treat acute myocardial infarction, have moved to the care of a broader population of acute cardiac patients and are currently defined as Intensive Cardiac Care Units (ICCUs). However, very limited data are available on such evolution. Since 2008, in Italy, several surveys have been designed to assess ICCUs' activities. The largest and most comprehensive of these, the BLITZ-3 Registry, observed that patients admitted are mainly elderly males and suffer from several comorbidities. Direct admission to ICCUs through the Emergency Medical System was rather rare. Acute coronary syndromes (ACS) account for more than half of the discharge diagnoses. However, numbers of acute heart failure (AHF) admissions are substantial. Interestingly, age, resources availability, and networking have a strong influence on ICCUs' epidemiology and activities. In fact, while patients with ACS concentrate in ICCUs with interventional capabilities, older patients with AHF or non-ACS, non-AHF cardiac diseases prevail in peripheral ICCUs. In conclusion, although ACS is still the core business of ICCUs, aging, comorbidities, increasing numbers of non-ACS, technological improvements, and resources availability have had substantial effects on epidemiology and activities of ICCUs. The Italian surveys confirm these changes and call for a substantial update of ICCUs' organization and competences.

Autographa californica multiple nucleopolyhedrovirus ac75 is required for egress of nucleocapsids from the nucleus and formation of de novo intranuclear membrane microvesicles.

Directory of Open Access Journals (Sweden)

Ya-Jun Guo

Full Text Available In this study, Autographa californica multiple nucleopolyhedrovirus ac75 was functionally characterized. Ac75 has homologs in all sequenced genomes of alphabaculoviruses, betabaculoviruses, and gammabaculoviruses. It was determined to encode a protein that is associated with the nucleocapsid of budded virus and with both envelope and nucleocapsids of occlusion-derived virus. Sf9 cells transfected by an ac75-knockout bacmid resulted in the infection being restricted to single cells. No budded virus were detected although viral DNA replication and late gene expression were unaffected. Electron microscopy revealed that the virogenic stroma, nucleocapsids and occlusion bodies appeared normal in the cells transfected by an ac75-knockout bacmid. However, the nucleocapsids were unenveloped, the occlusion bodies did not contain any virions or nucleocapsids, and no nucleocapsids were found outside the nucleus or spanning the nuclear membrane. In addition, de novo intranuclear membrane microvesicles that are the precursor of occlusion-derived virus envelopes were absent in the nuclei of transfected cells. Confocal microscopy showed that AC75 protein appeared in the cytoplasm as early as 6 hours post infection. It localized to the ring zone at the periphery of the nucleus from 15 to 24 hours post infection and demonstrated light blocky cloud-like distribution in the center of the nucleus. AC75 was found to co-immunoprecipitate with BV and ODV associated envelope protein ODV-E25. The data from this study suggest that ac75 is essential for induction of the intranuclear membrane microvesicles, it appears to be required for the intranuclear envelopment of nucleocapsids, and is also essential for egress of nucleocapsids from the nuclei, in infected cells.

Monolithic blue LED series arrays for high-voltage AC operation

Energy Technology Data Exchange (ETDEWEB)

Ao, Jin-Ping [Satellite Venture Business Laboratory, University of Tokushima, Tokushima 770-8506 (Japan); Sato, Hisao; Mizobuchi, Takashi; Morioka, Kenji; Kawano, Shunsuke; Muramoto, Yoshihiko; Sato, Daisuke; Sakai, Shiro [Nitride Semiconductor Co. Ltd., Naruto, Tokushima 771-0360 (Japan); Lee, Young-Bae; Ohno, Yasuo [Department of Electrical and Electronic Engineering, University of Tokushima, Tokushima 770-8506 (Japan)

2002-12-16

Design and fabrication of monolithic blue LED series arrays that can be operated under high ac voltage are described. Several LEDs, such as 3, 7, and 20, are connected in series and in parallel to meet ac operation. The chip size of a single device is 150 {mu}m x 120 {mu}m and the total size is 1.1 mm x 1 mm for a 40(20+20) LED array. Deep dry etching was performed as device isolation. Two-layer interconnection and air bridge are utilized to connect the devices in an array. The monolithic series array exhibit the expected operation function under dc and ac bias. The output power and forward voltage are almost proportional to LED numbers connected in series. On-wafer measurement shows that the output power is 40 mW for 40(20+20) LED array under ac 72 V. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

pH sensing via bicarbonate-regulated ‘soluble’ adenylyl cyclase (sAC

Directory of Open Access Journals (Sweden)

Nawreen eRahman

2013-11-01

Full Text Available Soluble adenylyl cyclase (sAC is a source of the second messenger cyclic adenosine 3',5' monophosphate (cAMP. sAC is directly regulated by bicarbonate (HCO3- ions. In living cells, HCO3- ions are in nearly instantaneous equilibrium with carbon dioxide (CO2 and pH due to the ubiquitous presence of carbonic anhydrases. Numerous biological processes are regulated by CO2, HCO3-, and/or pH, and in a number of these, sAC has been shown to function as a physiological CO2/HCO3/pH sensor. In this review, we detail the known pH sensing functions of sAC, and we discuss two highly-studied, pH-dependent pathways in which sAC might play a role.

Normal form of particle motion under the influence of an ac dipole

Directory of Open Access Journals (Sweden)

R. Tomás

2002-05-01

Full Text Available ac dipoles in accelerators are used to excite coherent betatron oscillations at a drive frequency close to the tune. These beam oscillations may last arbitrarily long and, in principle, there is no significant emittance growth if the ac dipole is adiabatically turned on and off. Therefore the ac dipole seems to be an adequate tool for nonlinear diagnostics provided the particle motion is well described in the presence of the ac dipole and nonlinearities. Normal forms and Lie algebra are powerful tools to study the nonlinear content of an accelerator lattice. In this article a way to obtain the normal form of the Hamiltonian of an accelerator with an ac dipole is described. The particle motion to first order in the nonlinearities is derived using Lie algebra techniques. The dependence of the Hamiltonian terms on the longitudinal coordinate is studied showing that they vary differently depending on the ac dipole parameters. The relation is given between the lines of the Fourier spectrum of the turn-by-turn motion and the Hamiltonian terms.

Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

Science.gov (United States)

Peak, S. C.

1982-01-01

An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

Analysis of Input and Output Ripples of PWM AC Choppers

Directory of Open Access Journals (Sweden)

Pekik Argo Dahono

2008-11-01

Full Text Available This paper presents an analysis of input and output ripples of PWM AC choppers. Expressions of input and output current and voltage ripples of single-phase PWM AC choppers are first derived. The derived expressions are then extended to three-phase PWM AC choppers. As input current and output voltage ripples specification alone cannot be used to determine the unique values of inductance and capacitance of the LC filters, an additional criterion based on the minimum reactive power is proposed. Experimental results are included in this paper to show the validity of the proposed analysis method.

Pantallas acústicas submarinas de material compuesto multilaminar con matriz metálica

OpenAIRE

Gallego, V.; Laguna, M.; Vázquez, A. J.

1999-01-01

7 pp.-- PACS nr.: 43.30.Ky.-- Comunicación presentada en los siguientes congresos: XXX Jornadas Nacionales de Acústica – TecniAcústica 1999. Encuentro Ibérico de Acústica (Ávila, 20-22 Octubre 1999).

ac superconducting articles

International Nuclear Information System (INIS)

Meyerhoff, R.W.

1977-01-01

A noval ac superconducting cable is described. It consists of a composite structure having a superconducting surface along with a high thermally conductive material wherein the superconducting surface has the desired physical properties, geometrical shape and surface finish produced by the steps of depositing a superconducting layer upon a substrate having a predetermined surface finish and shape which conforms to that of the desired superconducting article, depositing a supporting layer of material on the superconducting layer and removing the substrate, the surface of the superconductor being a replica of the substrate surface

Autonomous Operation of Hybrid Microgrid with AC and DC Sub-Grids

DEFF Research Database (Denmark)

Loh, Poh Chiang; Blaabjerg, Frede

2011-01-01

the power flow among all the sources distributed throughout the two types of sub-grids, which certainly is tougher than previous efforts developed for only either ac or dc microgrid. This wider scope of control has not yet been investigated, and would certainly rely on the coordinated operation of dc...... sources, ac sources and interlinking converters. Suitable control and normalization schemes are therefore developed for controlling them with results presented for showing the overall performance of the hybrid microgrid.......This paper investigates on the active and reactive power sharing of an autonomous hybrid microgrid. Unlike existing microgrids which are purely ac, the hybrid microgrid studied here comprises dc and ac sub-grids, interconnected by power electronic interfaces. The main challenge here is to manage...

A Floquet-Green's function approach to mesoscopic transport under ac bias

International Nuclear Information System (INIS)

Wu, B H; Cao, J C

2008-01-01

The current response of a mesoscopic system under a periodic ac bias is investigated by combining the Floquet theorem and the nonequilibrium Green's function method. The band structure of the lead under ac bias is fully taken into account by using appropriate self-energies in an enlarged Floquet space. Both the retarded and lesser Green's functions are obtained in the Floquet basis to account for the interference and interaction effects. In addition to the external ac bias, the time-varying Coulomb interaction, which is treated at the self-consistent Hartree-Fock level, provides another internal ac field. The numerical results show that the time-varying Coulomb field yields decoherence and reduces the ringing behavior of the current response to a harmonic bias

Optimal football strategies: AC Milan versus FC Barcelona

OpenAIRE

Papahristodoulou, Christos

2012-01-01

In a recent UEFA Champions League game between AC Milan and FC Barcelona, played in Italy (final score 2-3), the collected match statistics, classified into four offensive and two defensive strategies, were in favour of FC Barcelona (by 13 versus 8 points). The aim of this paper is to examine to what extent the optimal game strategies derived from some deterministic, possibilistic, stochastic and fuzzy LP models would improve the payoff of AC Milan at the cost of FC Barcelona.

Preliminary design of reactor coolant pump canned motor for AC600

International Nuclear Information System (INIS)

Deng Shaowen

1998-01-01

The reactor coolant pump canned motor of AC600 PWR is the kind of shielded motors with high moment of inertia, high reliability, high efficiency and nice starting performance. The author briefly presents the main feature, design criterion and technical requirements, preliminary design, computation results and analysis of performance of AC600 reactor coolant pump canned motor, and proposes some problems to be solved for study and design of AC600 reactor coolant pump canned motor

Analytical theory and possible detection of the ac quantum spin Hall effect.

Science.gov (United States)

Deng, W Y; Ren, Y J; Lin, Z X; Shen, R; Sheng, L; Sheng, D N; Xing, D Y

2017-07-11

We develop an analytical theory of the low-frequency ac quantum spin Hall (QSH) effect based upon the scattering matrix formalism. It is shown that the ac QSH effect can be interpreted as a bulk quantum pumping effect. When the electron spin is conserved, the integer-quantized ac spin Hall conductivity can be linked to the winding numbers of the reflection matrices in the electrodes, which also equal to the bulk spin Chern numbers of the QSH material. Furthermore, a possible experimental scheme by using ferromagnetic metals as electrodes is proposed to detect the topological ac spin current by electrical means.

The Hubble Legacy Archive ACS grism data

Science.gov (United States)

Kümmel, M.; Rosati, P.; Fosbury, R.; Haase, J.; Hook, R. N.; Kuntschner, H.; Lombardi, M.; Micol, A.; Nilsson, K. K.; Stoehr, F.; Walsh, J. R.

2011-06-01

A public release of slitless spectra, obtained with ACS/WFC and the G800L grism, is presented. Spectra were automatically extracted in a uniform way from 153 archival fields (or "associations") distributed across the two Galactic caps, covering all observations to 2008. The ACS G800L grism provides a wavelength range of 0.55-1.00 μm, with a dispersion of 40 Å/pixel and a resolution of ~80 Å for point-like sources. The ACS G800L images and matched direct images were reduced with an automatic pipeline that handles all steps from archive retrieval, alignment and astrometric calibration, direct image combination, catalogue generation, spectral extraction and collection of metadata. The large number of extracted spectra (73,581) demanded automatic methods for quality control and an automated classification algorithm was trained on the visual inspection of several thousand spectra. The final sample of quality controlled spectra includes 47 919 datasets (65% of the total number of extracted spectra) for 32 149 unique objects, with a median iAB-band magnitude of 23.7, reaching 26.5 AB for the faintest objects. Each released dataset contains science-ready 1D and 2D spectra, as well as multi-band image cutouts of corresponding sources and a useful preview page summarising the direct and slitless data, astrometric and photometric parameters. This release is part of the continuing effort to enhance the content of the Hubble Legacy Archive (HLA) with highly processed data products which significantly facilitate the scientific exploitation of the Hubble data. In order to characterize the slitless spectra, emission-line flux and equivalent width sensitivity of the ACS data were compared with public ground-based spectra in the GOODS-South field. An example list of emission line galaxies with two or more identified lines is also included, covering the redshift range 0.2 - 4.6. Almost all redshift determinations outside of the GOODS fields are new. The scope of science projects

Alpha decay 225 Ac → 221Fr

International Nuclear Information System (INIS)

Gromov, K. Ya.; Gorozhankin, V.M.; Malov, L.A.; Fominykh, V.I.; Tsupko-Sitnikov, V.V.; Chumin, V.G.; Jakushev, E.A.; Kudrya, S.A.; Sergienko, V.A.; Malikov, Sh.R.

2004-01-01

Full text: Considerable attention has been given to nuclei with A = 220 - 230 recently. In this region there occurs transition from the spherical to the deformed nuclear shape, which gives rise to some specific features in the nuclear structure. In particular, negative parity levels with low excitation energies have been found in even-even nuclei from this region [1, 2]. One of the nuclei allowing experimental investigation of the above properties is 221 Fr. The nuclide 221 Fr is from the region of isotopes which does not include stable nuclei and thus it cannot be studied in several-nucleon transfer reactions. In addition, the neutron excess in this nucleus makes it impossible to study the nucleus in reactions with heavy ions. Experimental information on the 221 Fr level structure can only be gained from investigation of the 225 Ac (T 1/2 = 10 days) alpha decay or the 221 Rn (T 1/2 = 25 min) beta decay. In the latter case the possibilities of the investigation are restricted by difficulties in making of 221 Rn sources. Therefore, most information on the structure and properties of 221 Fr is derived from investigation of the 225 Ac α -decay [3]. In-depth investigation of ( α - γ )- coincidences at the 225 Ac decay is carried out. Twenty-one new weak γ - rays are found; 18 γ-rays earlier ascribed to the 225 Ac decay are not confirmed. The quantitative analysis of the ( α - γ )- coincidences makes it possible to find the intensity of 221 Fr levels by the decay and multipolarities of five weak γ -transitions. The conversion electron spectrum is investigated in the range of 5 † 24 keV with a high (some 20 eV) energy resolution. A new M1 type 10.6-keV γ-transition is found. The proposed 225 Ac decay scheme includes 31 excited 221 Fr states. Parities are established for 16 of them. Possible spin values are proposed for 221 Fr levels. Properties of excited 221 Fr states are satisfactorily described by the quasiparticle-phonon nuclear model without the

Reducing AC-Winding Losses in High-Current High-Power Inductors

DEFF Research Database (Denmark)

Nymand, Morten; Madawala, Udaya K.; Andersen, Michael Andreas E.

2009-01-01

Foil windings are preferable in high-current high-power inductors to realize compact designs and to reduce dc-current losses. At high frequency, however, proximity effect will cause very significant increase in ac resistance in multi-layer windings, and lead to high ac winding losses. This paper ...

Tribological properties of AC44200 based composites strenghead with AlB2BOB3 Bparticles

OpenAIRE

J.W. Kaczmar; A. Janus; E. Grodzka; A. Kurzawa

2011-01-01

The paper presents a research on abrasion resistance of aluminium-based composites consisting of EN AC-44200 matrix reinforcedwith AlB2BOB3B particles. The examinations revealed that wear intensity of the composites decreased with increasing volume fraction of the particles. Much more intensive abrasive wear was observed on the first kilometre in comparison to the wear on the subsequent distances, i.e. from 1 to 3.5 km and from 3.5 to 8.5 km of the wear distance. Microscopic examinations perm...

Interlink Converter with Linear Quadratic Regulator Based Current Control for Hybrid AC/DC Microgrid

Directory of Open Access Journals (Sweden)

Dwi Riana Aryani

2017-11-01

Full Text Available A hybrid alternate current/direct current (AC/DC microgrid consists of an AC subgrid and a DC subgrid, and the subgrids are connected through the interlink bidirectional AC/DC converter. In the stand-alone operation mode, it is desirable that the interlink bidirectional AC/DC converter manages proportional power sharing between the subgrids by transferring power from the under-loaded subgrid to the over-loaded one. In terms of system security, the interlink bidirectional AC/DC converter takes an important role, so proper control strategies need to be established. In addition, it is assumed that a battery energy storage system is installed in one subgrid, and the coordinated control of interlink bidirectional AC/DC converter and battery energy storage system converter is required so that the power sharing scheme between subgrids becomes more efficient. For the purpose of designing a tracking controller for the power sharing by interlink bidirectional AC/DC converter in a hybrid AC/DC microgrid, a droop control method generates a power reference for interlink bidirectional AC/DC converter based on the deviation of the system frequency and voltages first and then interlink bidirectional AC/DC converter needs to transfer the power reference to the over-loaded subgrid. For efficiency of this power transferring, a linear quadratic regulator with exponential weighting for the current regulation of interlink bidirectional AC/DC converter is designed in such a way that the resulting microgrid can operate robustly against various uncertainties and the power sharing is carried out quickly. Simulation results show that the proposed interlink bidirectional AC/DC converter control strategy provides robust and efficient power sharing scheme between the subgrids without deteriorating the secure system operation.

On-Chip AC self-test controller

Science.gov (United States)

Flanagan, John D [Rhinebeck, NY; Herring, Jay R [Poughkeepsie, NY; Lo, Tin-Chee [Fishkill, NY

2009-09-29

A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

The Use of AC-DC-AC Methods in Assessing Corrosion Resistance Performance of Coating Systems for Magnesium Alloys

Science.gov (United States)

McCune, Robert C.; Upadhyay, Vinod; Wang, Yar-Ming; Battocchi, Dante

The potential utility of AC-DC-AC electrochemical methods in comparative measures of corrosion-resisting coating system performance for magnesium alloys under consideration for the USAMP "Magnesium Front End Research and Development" project was previously shown in this forum [1]. Additional studies of this approach using statistically-designed experiments have been conducted with focus on alloy types, pretreatment, topcoat material and topcoat thickness as the variables. Additionally, sample coupons made for these designed experiments were also subjected to a typical automotive cyclic corrosion test cycle (SAE J2334) as well as ASTM B117 for comparison of relative performance. Results of these studies are presented along with advantages and limitations of the proposed methodology.

Roebel assembled coated conductor cables (RACC): Ac-Losses and current carrying potential

Science.gov (United States)

Frank, A.; Heller, R.; Goldacker, W.; Kling, A.; Schmidt, C.

2008-02-01

Low ac-loss HTS cables for transport currents well above 1 kA are required for application in transformers and generators and are taken into consideration for future generations of fusion reactor coils. Coated conductors (CC) are suitable candidates for high field application at an operation temperature in the range 50-77 K. Ac-field applications require cables with low ac-losses and hence twisting of the individual strands. We solved this problem using the Roebel technique. Short lengths of Roebel bar cables were prepared from industrial DyBCO and YBCO-CC. Meander shaped tapes of 4 or 5 mm width with twist pitches of 123 or 127 mm were cut from the 10 or 12 mm wide CC tapes using a specially designed tool. Eleven or twelve of these strands were assembled to a cable. The electrical and mechanical connection of the tapes was achieved using a silver powder filled conductive epoxy resin. Ac-losses of a short sample in an external ac-field were measured as a function of frequency and field amplitude as well as the coupling current decay time constant. We discuss the results in terms of available theories and compare measured time constants in transverse field with measured coupling losses. Finally the potential of this cable type for ac-use is discussed with respect to ac-losses and current carrying capability.

Roebel assembled coated conductor cables (RACC): Ac-Losses and current carrying potential

International Nuclear Information System (INIS)

Frank, A; Heller, R; Goldacker, W; Kling, A; Schmidt, C

2008-01-01

Low ac-loss HTS cables for transport currents well above 1 kA are required for application in transformers and generators and are taken into consideration for future generations of fusion reactor coils. Coated conductors (CC) are suitable candidates for high field application at an operation temperature in the range 50-77 K. Ac-field applications require cables with low ac-losses and hence twisting of the individual strands. We solved this problem using the Roebel technique. Short lengths of Roebel bar cables were prepared from industrial DyBCO and YBCO-CC. Meander shaped tapes of 4 or 5 mm width with twist pitches of 123 or 127 mm were cut from the 10 or 12 mm wide CC tapes using a specially designed tool. Eleven or twelve of these strands were assembled to a cable. The electrical and mechanical connection of the tapes was achieved using a silver powder filled conductive epoxy resin. Ac-losses of a short sample in an external ac-field were measured as a function of frequency and field amplitude as well as the coupling current decay time constant. We discuss the results in terms of available theories and compare measured time constants in transverse field with measured coupling losses. Finally the potential of this cable type for ac-use is discussed with respect to ac-losses and current carrying capability

AC conductivity for a holographic Weyl semimetal

Energy Technology Data Exchange (ETDEWEB)

Grignani, Gianluca; Marini, Andrea; Peña-Benitez, Francisco; Speziali, Stefano [Dipartimento di Fisica e Geologia, Università di Perugia,I.N.F.N. Sezione di Perugia,Via Pascoli, I-06123 Perugia (Italy)

2017-03-23

We study the AC electrical conductivity at zero temperature in a holographic model for a Weyl semimetal. At small frequencies we observe a linear dependence in the frequency. The model shows a quantum phase transition between a topological semimetal (Weyl semimetal phase) with a non vanishing anomalous Hall conductivity and a trivial semimetal. The AC conductivity has an intermediate scaling due to the presence of a quantum critical region in the phase diagram of the system. The phase diagram is reconstructed using the scaling properties of the conductivity. We compare with the experimental data of https://www.doi.org/10.1103/PhysRevB.93.121110 obtaining qualitative agreement.

Comparative transcriptome analysis reveals distinct ethylene-independent regulation of ripening in response to low temperature in kiwifruit.

Science.gov (United States)

Asiche, William O; Mitalo, Oscar W; Kasahara, Yuka; Tosa, Yasuaki; Mworia, Eric G; Owino, Willis O; Ushijima, Koichiro; Nakano, Ryohei; Yano, Kentaro; Kubo, Yasutaka

2018-03-21

Kiwifruit are classified as climacteric since exogenous ethylene (or its analogue propylene) induces rapid ripening accompanied by ethylene production under positive feedback regulation. However, most of the ripening-associated changes (Phase 1 ripening) in kiwifruit during storage and on-vine occur largely in the absence of any detectable ethylene. This ripening behavior is often attributed to basal levels of system I ethylene, although it is suggested to be modulated by low temperature. To elucidate the mechanisms regulating Phase 1 ripening in kiwifruit, a comparative transcriptome analysis using fruit continuously exposed to propylene (at 20 °C), and during storage at 5 °C and 20 °C was conducted. Propylene exposure induced kiwifruit softening, reduction of titratable acidity (TA), increase in soluble solids content (SSC) and ethylene production within 5 days. During storage, softening and reduction of TA occurred faster in fruit at 5 °C compared to 20 °C although no endogenous ethylene production was detected. Transcriptome analysis revealed 3761 ripening-related differentially expressed genes (DEGs), of which 2742 were up-regulated by propylene while 1058 were up-regulated by low temperature. Propylene exclusively up-regulated 2112 DEGs including those associated with ethylene biosynthesis and ripening such as AcACS1, AcACO2, AcPL1, AcXET1, Acβ-GAL, AcAAT, AcERF6 and AcNAC7. Similarly, low temperature exclusively up-regulated 467 DEGS including AcACO3, AcPL2, AcPMEi, AcADH, Acβ-AMY2, AcGA2ox2, AcNAC5 and AcbZIP2 among others. A considerable number of DEGs such as AcPG, AcEXP1, AcXET2, Acβ-AMY1, AcGA2ox1, AcNAC6, AcMADS1 and AcbZIP1 were up-regulated by either propylene or low temperature. Frequent 1-MCP treatments failed to inhibit the accelerated ripening and up-regulation of associated DEGs by low temperature indicating that the changes were independent of ethylene. On-vine kiwifruit ripening proceeded in the absence of any detectable

Graduate Education in Chemistry. The ACS Committee on Professional Training: Surveys of Programs and Participants.

Science.gov (United States)

American Chemical Society, Washington, DC.

This document reports on graduate education in chemistry concerning the nature of graduate programs. Contents include: (1) "Graduate Education in Chemistry in the United States: A Snapshot from the Late Twentieth Century"; (2) "A Survey of Ph.D. Programs in Chemistry"; (4) "The Master's Degree in Chemistry"; (5) "A Survey of Ph.D. Recipients in…

The methylenetetrahydrofolate reductase c.c.677 C>T and c.c.1298 A>C polymorphisms in reproductive failures: Experience from an RSA and RIF study on a Polish population.

Science.gov (United States)

Nowak, Izabela; Bylińska, Aleksandra; Wilczyńska, Karolina; Wiśniewski, Andrzej; Malinowski, Andrzej; Wilczyński, Jacek R; Radwan, Paweł; Radwan, Michał; Barcz, Ewa; Płoski, Rafał; Motak-Pochrzęst, Hanna; Banasik, Małgorzata; Sobczyński, Maciej; Kuśnierczyk, Piotr

2017-01-01

Almost 1600 individuals from the Polish population were recruited to this study. Among them 319 were fertile couples, 289 were recurrent spontaneous abortion (RSA) couples, and 131 were in the group of recurrent implantation failure (RIF) following in vitro fertilization. The aim of this study was to evaluate the MTHFR c.c.677 C>T and c.c.1298 A>C polymorphisms' association with RSA and RIF. We used PCR-RFLP with HinfI (677 C>T) and MboII (1298 A>C) digestion. We observed a protective effect of the female AC genotype (OR = 0.64, p = 0.01) and the C allele (AC+CC genotypes; OR = 0.65, p = 0.009) against RSA. Moreover, 1298 AA/677 CT women were more frequent in RSA (31.14%) and RIF (25.20%) groups in comparison to fertile women (22.88%), although this difference was significant only in the case of RSA (p = 0.022, OR = 1.52). Male combined genotype analysis revealed no association with reproductive failure of their partners. Nevertheless, the female/male combination AA/AC of the 1298 polymorphism was more frequent in RSA couples (p = 0.049, OR = 1.49). However, the significant results became insignificant after Bonferroni correction. In addition, analysis of haplotypes showed significantly higher frequency of the C/C haplotype (1298 C/677 C) in the female control group than in the female RSA group (p = 0.03, OR = 0.77). Moreover, the association between elevated homocysteine (Hcy) level in plasma of RSA and RIF women and MTHFR polymorphisms was investigated but did not reveal significant differences. In conclusion, for clinical practice, it is better to check the homocysteine level in plasma and, if the Hcy level is increased, to recommend patients to take folic acid supplements rather than undergo screening of MTHFR for 1298 A>C and 677 C>T polymorphisms.

Calculation of single phase AC and monopolar DC hybrid corona effects

International Nuclear Information System (INIS)

Zhao, T.; Sebo, S.A.; Kasten, D.G.

1996-01-01

Operating a hybrid HVac and HVdc line is an option for increasing the efficiency of power transmission and overcoming the difficulties in obtaining a new right-of-way. This paper proposes a new calculation method for the study of hybrid line corona. The proposed method can be used to calculate dc corona losses and corona currents in dc or ac conductors for single phase ac and monopolar dc hybrid lines. Profiles of electric field strength and ion current density at ground level can be estimated. The effects of the presence of an energized ac conductor on dc conductor corona and dc voltage on ac conductor corona are included in the method. Full-scale and reduced-scale experiments were utilized to investigate the hybrid line corona effects. Verification of the proposed calculation method is given

Dielectric and AC-conductivity studies of Dy2O3 doped (K0.5Na0.5NbO3 ceramics

Directory of Open Access Journals (Sweden)

Mahesh Peddigari

2014-08-01

Full Text Available (K0.5Na0.5NbO3 + x wt.% Dy2O3 (x = 0–1.5 ferroelectric ceramics were prepared by conventional solid state reaction method. XRD patterns revealed that orthorhombic symmetry has transformed into psuedocubic symmetry with increasing the substitution of Dy3+ in the Na+ site. Temperature and frequency dependences of relative dielectric permittivity maximum conforms the transformation from normal ferroelectric to relaxor ferroelectric behaviour. Frequency dependence of the relative dielectric permittivity maximum temperature observed for the samples with x ≥ 1.0 and satisfied the Vogel–Fulcher law. The diffuseness exponent γ (1.27–1.95 estimated from the high temperature slopes of the diffused dielectric permittivity data reveals that the degree of relaxor behavior increases with increasing the amount of Dy2O3. The temperature dependence of AC-conductivity σAC (T analysis in the range 310 K < T < 470 K reveals the existence of variable range hopping of charge carriers with average hopping length RH and hopping energy EH are in the range 8.5–27 Å and 48–153 meV, respectively. Voltage dependent dielectric constant measurements confirm the ferroelectric nature of KNN+ x wt% Dy2O3 ceramics.

Power Controllability of Three-phase Converter with Unbalanced AC Source

DEFF Research Database (Denmark)

Ma, Ke; Chen, Wenjie; Liserre, Marco

2015-01-01

Three-phase DC-AC power converters suffer from power oscillation and overcurrent problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... currents. In this work a new series of control strategies which utilize the zerosequence components are proposed to enhance the power control ability under this adverse condition. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC voltage....

A direct power conversion topology for grid integrations of hybrid AC/DC resources

DEFF Research Database (Denmark)

Liu, Xiong; Loh, Poh Chiang; Wang, Peng

2012-01-01

and modulation schemes are proposed to extract the commanded current from the input ac/dc sources to the grid and guarantee high quality ac/dc inputs and ac output current waveforms with unity power factors. The proposed modulation scheme for sinusoidal outputs of the VMC is mathematically proved...

Low frequency ac conduction and dielectric relaxation in poly(N ...

Indian Academy of Sciences (India)

The ac conductivity and dielectric constant of poly(N-methyl pyrrole) thin films have been investigated in the temperature range 77–350 K and in the frequency range 102–106 Hz. The well defined loss peaks have been observed in the temperature region where measured ac conductivity approaches dc conductivity.

Productos «Celotex» para acondicionamientos Acústicos

Directory of Open Access Journals (Sweden)

Editorial, Equipo

1958-02-01

Full Text Available Not availableBajo la denominación general «Celotex», que es un nombre registrado, la Casa Americana The Celotex Corporation, cuyo domicilio social es 120 South, La Salle Street, Chicago J. lllinois, fabrica diversos materiales para fines de acondicionamiento acústico elaborados, según los tipos de que se trate, con fibra de caña de azúcar, lanas minerales, acero, amianto, etc., perforados o no y de acuerdo con el efecto estético y acústico que se desee obtener.

CTE Corrections for WFPC2 and ACS

Science.gov (United States)

Dolphin, Andrew

2003-07-01

The error budget for optical broadband photometry is dominated by three factors: CTE corrections, long-short anomaly corrections, and photometric zero points. Questions about the dependencies of the CTE have largely been resolved, and my CTE corrections have been included in the WFPC2 handbook and tutorial. What remains to be done is the determination of the "final" CTE correction at the end of the WFPC2 mission, which will increase the accuracy of photometry obtained in the final few cycles. The long-short anomaly is still the subject of much debate, as it remains unclear whethere or not this effect is real and, if so, what its size and nature is. Photometric zero points have likewise varied by over 0.05 magnitudes in the literature, and will likely remain unresolved until the long-short anomaly is addressed {given that most calibration exposures are short while most science exposures are long}. It is also becoming apparent that similar issues will affect the accuracy of ACS photometry, and consequently that an ACS CTE study analogous to my WFPC2 work would significantly improve the calibration of ACS. I therefore propose to use archival WFPC2 images of omega Cen and ACS images of 47 Tuc to continue my HST calibration work. I also propose to begin work on "next-generation" CTE corrections, in which corrections are applied to the images based on accurate charge-trapping models rather than to the reduced photometry. This technique will allow for more accurate CTE corrections in certain cases {such as a star above a bright star or on a variable background}, improved PSF-fitting photometry of faint stars, and image restoration for accurate analysis of extended objects.

Superconducting ac cable

Science.gov (United States)

Schmidt, F.

1980-11-01

The components of a superconducting 110 kV ac cable for power ratings or = 2000 MVA were developed. The cable design is of the semiflexible type, with a rigid cryogenic envelope containing a flexible hollow coaxial cable core. The cable core consists of spirally wound Nb-A1 composite wires electrically insulated by high pressure polyethylene tape wrappings. A 35 m long single phase test cable with full load terminals rated at 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of this cable design.

Superconducting ac cable

International Nuclear Information System (INIS)

Schmidt, F.

1980-01-01

The components of a superconducting 110 kV ac cable for power ratings >= 2000 MVA have been developed. The cable design especially considered was of the semiflexible type, with a rigid cryogenic envelope and flexible hollow coaxial cable cores pulled into the former. The cable core consists of spirally wound Nb-Al composite wires and a HDPE-tape wrapped electrical insulation. A 35 m long single phase test cable with full load terminations for 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of our cable design. (orig.) [de

Both flagella and F4 fimbriae from F4ac+ enterotoxigenic Escherichia coli contribute to attachment to IPEC-J2 cells in vitro.

Science.gov (United States)

Zhou, Mingxu; Duan, Qiangde; Zhu, Xiaofang; Guo, Zhiyan; Li, Yinchau; Hardwidge, Philip R; Zhu, Guoqiang

2013-05-13

The role of flagella in the pathogenesis of F4ac+ Enterotoxigenic Escherichia coli (ETEC) mediated neonatal and post-weaning diarrhea (PWD) is not currently understood. We targeted the reference C83902 ETEC strain (O8:H19:F4ac+ LT+ STa+ STb+), to construct isogenic mutants in the fliC (encoding the major flagellin protein), motA (encoding the flagella motor), and faeG (encoding the major subunit of F4 fimbriae) genes. Both the ΔfliC and ΔfaeG mutants had a reduced ability to adhere to porcine intestinal epithelial IPEC-J2 cells. F4 fimbriae expression was significantly down-regulated after deleting fliC, which revealed that co-regulation exists between flagella and F4 fimbriae. However, there was no difference in adhesion between the ΔmotA mutant and its parent strain. These data demonstrate that both flagella and F4 fimbriae are required for efficient F4ac+ ETEC adhesion in vitro.

Complex study of transport AC loss in various 2G HTS racetrack coils

Energy Technology Data Exchange (ETDEWEB)

Chen, Yiran, E-mail: yc315@cam.ac.uk [University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Zhang, Min; Chudy, Michal; Matsuda, Koichi; Coombs, Tim [University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom)

2013-04-15

Highlights: ► Comparing transport AC losses of two types of 2G HTS racetrack coils. ► The magnetic substrate in the MAG RABITS coil is the main difference. ► Experimental data agree well with simulation results. ► The transport AC loss in the MAG RABITS coil is 36% higher than that in the IBAD coil. ► It is better to keep all the substrate non-magnetic. -- Abstract: HTS racetrack coils are becoming important elements of an emerging number of superconducting devices such as generators or motors. In these devices the issue of AC loss is crucial, as performance and cooling power are derived from this quantity. This paper presents a comparative study of transport AC loss in two different types of 2G HTS racetrack coils. In this study, both experimental measurements and computer simulation approaches were employed. All the experiments were performed using classical AC electrical method. The finite-element computer model was used to estimate electromagnetic properties and calculate transport AC loss. The main difference between the characterized coils is covered inside tape architectures. While one coil uses tape based on RABITS magnetic substrate, the second coil uses a non-magnetic tape. Ferromagnetic loss caused by a magnetic substrate is an important issue involved in the total AC loss. As a result, the coil with the magnetic substrate surprised with high AC loss and rather low performance.

a.c. conductance study of polycrystal C{sub 60}

Energy Technology Data Exchange (ETDEWEB)

Yan Feng [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Wang Yening [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Huang Yineng [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Gu Min [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Zhang Qingming [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Shen Huimin [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure

1995-06-05

The a.c. (1a.c. conductance is nearly proportional to the temperature and frequency. This is proposed to be due to the hopping of localized states around the Fermi level. Above 200 K, the a.c. conductance exhibits a rapid increase with temperature, and shows a thermally activated behaviour with an activation energy of 0.389 eV below a certain temperature and 0.104 eV above it. A frequency dependent conductance at a fixed temperature is also obtained with a power law {sigma} similar {omega}{sup s} (s{approx}0.8). For a sample of normal grain size, we have measured a peak near 250 K and a much smaller conductance. These results indicate that the defective na ture of our sample (small grain size, disorder or impurities) plays an important role for the transport properties. The existence of nanocrystals in the sample may give rise to localized states and improve its a.c. conductance. The two activation energies can be attributed to the coexistence of the crystalline and amorphous phases of C{sub 60}. ((orig.)).

Faradaic AC Electrokinetic Flow and Particle Traps

Science.gov (United States)

Ben, Yuxing; Chang, Hsueh-Chia

2004-11-01

Faradaic reaction at higher voltages can produce co-ion polarization at AC electrodes instead of counter-ion polarization due to capacitive charging from the bulk. The Faradaic co-ion polarization also does not screen the external field and hence can produce large net electro-kinetic flows at frequencies lower than the inverse RC time of the double layer. Due to the opposite polarization of capacitve and Faradaic charging, we can reverse the direction of AC flows on electrodes by changing the voltage and frequency. Particles and bacteria are trapped and then dispersed at stagnation lines, at locations predicted by our theory, by using these two flows sequentially. This technique offers a good way to concentrate and detect bacteria.

AC application of second generation HTS wire

Science.gov (United States)

Thieme, C. L. H.; Gagnon, K.; Voccio, J.; Aized, D.; Claassen, J.

2008-02-01

For the production of Second Generation (2G) YBCO High Temperature Superconductor wire American Superconductor uses a wide-strip MOD-YBCO/RABiTSTM process, a low-cost approach for commercial manufacturing. It can be engineered with a high degree of flexibility to manufacture practical 2G conductors with architectures and properties tailored for specific applications and operating conditions. For ac applications conductor and coil design can be geared towards low hysteretic losses. For applications which experience high frequency ac fields, the stabilizer needs to be adjusted for low eddy current losses. For these applications a stainless-steel laminate is used. An example is a Low Pass Filter Inductor which was developed and built in this work.

AC Losses and Their Thermal Effect in High Temperature Superconducting Machines

DEFF Research Database (Denmark)

Song, Xiaowei (Andy); Mijatovic, Nenad; Zou, Shengnan

2015-01-01

In transient operations or fault conditions, high temperature superconducting (HTS) machines suffer AC losses which have an influence on the thermal stability of superconducting windings. In this paper, a method to calculate AC losses and their thermal effect in HTS machines is presented....... The method consists of three sub-models that are coupled only in one direction. The magnetic field distribution is first solved in a machine model, assuming a uniform current distribution in HTS windings. The magnetic fields on the boundaries are then used as inputs for an AC loss model which has...

AC Losses and Their Thermal Effect in High-Temperature Superconducting Machines

DEFF Research Database (Denmark)

Song, Xiaowei (Andy); Mijatovic, Nenad; Zou, Shengnan

2016-01-01

In transient operations or fault conditions, hightemperature superconducting (HTS) machines suffer ac losses, which have an influence on the thermal stability of superconducting windings. In this paper, a method to calculate ac losses and their thermal effect in HTS machines is presented....... The method consists of three submodels that are coupled only in one direction. The magnetic field distribution is first solved in a machine model, assuming a uniform current distribution in HTS windings. The magnetic fields on the boundaries are then used as inputs for an ac loss model that has a homogeneous...

ELECTRONIC SYSTEM FOR EXPERIMENTATION IN AC ELECTROGRAVIMETRY I: TECHNIQUE FUNDAMENTALS

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Róbinson Torres

Full Text Available Basic fundamentals of AC electrogravimetry are introduced. Their main requirements and characteristics are detailed to establish the design of an electronic system that allows the appropriate extraction of data needed to determine the electrogravimetric transfer function (EGTF and electrochemical impedance (EI, in an experimental set-up for the AC electrogravimetry technique.

AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

International Nuclear Information System (INIS)

Nagendra, K.; Babu, G. Satish; Gowda, Veeranna; Reddy, C. Narayana

2011-01-01

Glasses in the system xLi 2 SO 4 -20Li 2 O-(80-x) [80P 2 O 5 -20V 2 O 5 ](5≥x≥20 mol%) has been prepared by melt quenching method. Dc and ac conductivity has been studied over a wide range of frequency (10 Hz to 10 MHz) and temperature (298 K-523 K). The dc conductivity found to increase with increase of Li 2 SO 4 concentration. The ac conductivities have been fitted to the Almond-West type single power law equation σ(ω) = σ(0)+Aω s where 's' is the power law exponent. The ac conductivity found to increase with increase of Li 2 SO 4 concentration. An attempt is made to elucidate the enhancement of lithium ion conduction in phosphor-vanadate glasses by considering the expansion of network structure.

The Pan-STARRS Survey for Transients (PSST)

Science.gov (United States)

Huber, Mark; Carter Chambers, Kenneth; Flewelling, Heather; Smartt, Stephen J.; Smith, Ken; Wright, Darryl

2015-08-01

The Pan-STARRS1 (PS1) Science Consortium finished the 3Pi survey of the whole sky north of -30 degrees between 2010-2014 in grizy (PS1 specific filters) and the PS1 telescope has been running a wide-field survey for near earth objects, funded by NASA through the NEO Observation Program. This survey takes data in a w-band (wide-band filter spanning g,r,i) in dark time, and combinations of r, i, z and y during bright time. We are now processing these data through the Pan-STARRS IPP difference imaging pipeline and recovering stationary transients. Effectively the 3Pi survey for transients that started during the PS1 Science Consortium is being continued under the new NEO optimized operations mode. The observing procedure in this case is to take a quad of exposures, typically 30-45 seconds separated by 10-20 minutes each, typically revealing high confidence transients (greater than 5-sigma) to depths of i~ 20.7, y~18.3 (AB mags). This cadence may be repeated on subsequent nights in a return pointing.Continuing the public release of the first 880 transients from the PS1 3Pi survey during the search period September 2013 - January 2014, beginning February 2015, the transient events using the data from the the Pan-STARRS NEO Science Consortium are now regularly added. These are mostly supernova candidates, but the list also contains some variable stars, AGN, and nuclear transients. The light curves are too sparsely sampled to be of standalone use, but they may be of use to the community in combining with existing data (e.g. Fraser et al. 2013, ApJ, 779, L8), constraining explosion and rise times (e.g. Nicholl et al. 2013, Nature, 502, 346) as well as many being new discoveries.For additional details visit http://star.pst.qub.ac.uk/ps1threepi/

Non-Federal participation in AC Intertie: Final environmental impact statement

International Nuclear Information System (INIS)

1994-01-01

Bonneville Power Administration (BPA) is considering action in two areas: (1) non-Federal access to the AC Intertie, and, (2) BPA Intertie marketing. BPA's preferred alternative for non-Federal access is the Capacity Ownership alternative combined with the Increased Assured Delivery -- Access for Non-Scheduling Utilities alternative; the preferred alternative for BPA Intertie marketing is the Federal Marketing and Joint Ventures alternative. BPA considered these two areas previously in its Intertie Development and Use EIS of April 1988. The EIS resulted in BPA decisions to participate in the construction of the Third AC Intertie, to allow non-Federal access to BPA's share of the Pacific Northwest-Pacific Southwest (PNW-PSW) Intertie (AC and DC lines) pursuant to a Long-Term Intertie Access Policy (LTIAP), and to pursue BPA's export marketing alternative. The decision on allowing direct financial non-Federal participation in the Third AC line was deferred to a later, separate process, examined here. Also, BPA's export marketing objectives must now be examined in view of changed operations of Columbia River hydro facilities for improved fish survival

AC-loss considerations of a pulse SMES for an accelerator

International Nuclear Information System (INIS)

Lyly, M; Hiltunen, I; Jaervelae, J; Korpela, A; Lehti, L; Stenvall, A; Mikkonen, R

2010-01-01

In particle accelerators quasi-DC superconducting magnets are used to keep particles in desired tracks. The needed rapid field variations of these high energy magnets require large energy bursts. If these bursts are taken from and fed back to the utility grid, its voltage is distorted and the quality of the electricity degrades. In addition, these bursts may decrease operation life time of generators and extra arrangements may be required by the electricity producers. Thus, an energy storage is an essential component for a cost-effective particle accelerator. Flywheels, capacitors and superconducting magnetic energy storage (SMES) are possible options for these relatively large and high power energy storages. Here we concentrate on AC-loss of a pulse SMES aiming to demonstrate the feasibility of NbTi SMES in a particle accelerator. The designing of a SMES requires highly reliable AC-loss simulations. In this paper, calorimetric AC-loss measurements of a NbTi magnet have been carried out to consider conductor's suitability in a pulse SMES. In addition, the measured results are compared with AC-loss simulations.

Adaptive Intervention Methodology for Reduction of Respondent Contact Burden in the American Community Survey

Directory of Open Access Journals (Sweden)

Ashmead Robert

2017-12-01

Full Text Available The notion of respondent contact burden in sample surveys is defined, and a multi-stage process to develop policies for curtailing nonresponse follow-up is described with the goal of reducing this burden on prospective survey respondents. The method depends on contact history paradata containing information about contact attempts both for respondents and for sampled nonrespondents. By analysis of past data, policies to stop case follow-up based on control variables measured in paradata can be developed by calculating propensities to respond for paradata-defined subgroups of sampled cases. Competing policies can be assessed by comparing outcomes (lost interviews, numbers of contacts, patterns of reluctant participation, or refusal to participate as if these stopping policies had been followed in past data. Finally, embedded survey experiments may be used to assess contact-burden reduction policies when these are implemented in the field. The multi-stage method described here abstracts the stages followed in a series of research studies aimed at reducing contact burden in the Computer Assisted Telephone Interview (CATI and Computer Assisted Personal Interview (CAPI modes of the American Community Survey (ACS, which culminated in implementation of policy changes in the ACS.

A Switched Capacitor Based AC/DC Resonant Converter for High Frequency AC Power Generation

Directory of Open Access Journals (Sweden)

Cuidong Xu

2015-09-01

Full Text Available A switched capacitor based AC-DC resonant power converter is proposed for high frequency power generation output conversion. This converter is suitable for small scale, high frequency wind power generation. It has a high conversion ratio to provide a step down from high voltage to low voltage for easy use. The voltage conversion ratio of conventional switched capacitor power converters is fixed to n, 1/n or −1/n (n is the switched capacitor cell. In this paper, A circuit which can provide n, 1/n and 2n/m of the voltage conversion ratio is presented (n is stepping up the switched capacitor cell, m is stepping down the switching capacitor cell. The conversion ratio can be changed greatly by using only two switches. A resonant tank is used to assist in zero current switching, and hence the current spike, which usually exists in a classical switching switched capacitor converter, can be eliminated. Both easy operation and efficiency are possible. Principles of operation, computer simulations and experimental results of the proposed circuit are presented. General analysis and design methods are given. The experimental result verifies the theoretical analysis of high frequency AC power generation.

Lamin A/C mutations with lipodystrophy, cardiac abnormalities, and muscular dystrophy

NARCIS (Netherlands)

van der Kooi, A. J.; Bonne, G.; Eymard, B.; Duboc, D.; Talim, B.; van der Valk, M.; Reiss, P.; Richard, P.; Demay, L.; Merlini, L.; Schwartz, K.; Busch, H. F. M.; de Visser, M.

2002-01-01

Mutations in the lamin A/C gene are found in Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy with cardiac conduction disturbances, dilated cardiomyopathy with conduction system disease, and familial partial lipodystrophy. Cases with lamin A/C mutations presenting with lipodystrophy

Power Controllability of Three-phase Converter with Unbalanced AC Source

DEFF Research Database (Denmark)

Ma, Ke; Liserre, Marco; Blaabjerg, Frede

2013-01-01

Three-phase DC-AC power converters suffer from power oscillation and overcurrentt problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... currents. In this work a new series of control strategies which utilize the zero-sequence components are proposed to enhance the power control ability under this adverse conditions. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC sources....

AC Application of HTS Conductors in Highly Dynamic Electric Motors

International Nuclear Information System (INIS)

Oswald, B; Best, K-J; Setzer, M; Duffner, E; Soell, M; Gawalek, W; Kovalev, L K

2006-01-01

Based on recent investigations we design highly dynamic electric motors up to 400 kW and linear motors up to 120 kN linear force using HTS bulk material and HTS tapes. The introduction of HTS tapes into AC applications in electric motors needs fundamental studies on double pancake coils under transversal magnetic fields. First theoretical and experimental results on AC field distributions in double-pancake-coils and corresponding AC losses will be presented. Based on these results the simulation of the motor performance confirms extremely high power density and efficiency of both types of electric motors. Improved characteristics of rare earth permanent magnets used in our motors at low temperatures give an additional technological benefit

AC ignition of HID lamps

NARCIS (Netherlands)

Sobota, A.; Kanters, J.H.M.; Manders, F.; Veldhuizen, van E.M.; Haverlag, M.

2010-01-01

Our aim was to examine the starting behaviour of mid-pressure argon discharges in pin-pin (point-to-point) geometry, typically used in HID lamps. We focused our work on AC ignition of 300 and 700 mbar Ar discharges in Philips 70W standard burners. Frequency was varied between 200 kHz and 1 MHz. In

AC-Induced Bias Potential Effect on Corrosion of Steels

Science.gov (United States)

2009-02-05

induction, variable conduction Experimental Setup Super- martensitic stainless steel composition Analysis: C Mn Si Cr Ni Mo Cu N Typical 13 Cr ɘ.01 0.6... stainless steel used in pipelines. •Low carbon (ɘ.01): allows the formation of a “soft” martensite that is more resistant than standard martensitic ...Proposed AC Corrosion Models  AC Simulated Corrosion testing  Stainless steel pipe and coating  Cathodic protection  Experimental Setup  Preliminary

AC losses in horizontally parallel HTS tapes for possible wireless power transfer applications

Science.gov (United States)

Shen, Boyang; Geng, Jianzhao; Zhang, Xiuchang; Fu, Lin; Li, Chao; Zhang, Heng; Dong, Qihuan; Ma, Jun; Gawith, James; Coombs, T. A.

2017-12-01

This paper presents the concept of using horizontally parallel HTS tapes with AC loss study, and the investigation on possible wireless power transfer (WPT) applications. An example of three parallel HTS tapes was proposed, whose AC loss study was carried out both from experiment using electrical method; and simulation using 2D H-formulation on the FEM platform of COMSOL Multiphysics. The electromagnetic induction around the three parallel tapes was monitored using COMSOL simulation. The electromagnetic induction and AC losses generated by a conventional three turn coil was simulated as well, and then compared to the case of three parallel tapes with the same AC transport current. The analysis demonstrates that HTS parallel tapes could be potentially used into wireless power transfer systems, which could have lower total AC losses than conventional HTS coils.

The effect of ac magnetic fields on the lifting power of levitating superconductors

International Nuclear Information System (INIS)

Smolyak, B M; Ermakov, G V; Chubraeva, L I

2007-01-01

This study deals with the decrease in the levitation force under the action of an ac field up to the frequency at which oscillations of the superconducting suspension are limited by inertia. The lifting force was measured as a function of the ac field amplitude and the exposure time. It was shown that the force quickly decreased at the moment the ac field was applied and then continued diminishing, but at a lower rate. A qualitative model was proposed, taking into account two effects of the ac field on the magnetization of the levitating superconductor: a complete destruction of the critical state in some section of the superconductor (to a depth λ ac ) and the initiation of a faster magnetic relaxation in the region where the induction gradient is preserved

AC Electric Field Communication for Human-Area Networking

Science.gov (United States)

Kado, Yuichi; Shinagawa, Mitsuru

We have proposed a human-area networking technology that uses the surface of the human body as a data transmission path and uses an AC electric field signal below the resonant frequency of the human body. This technology aims to achieve a “touch and connect” intuitive form of communication by using the electric field signal that propagates along the surface of the human body, while suppressing both the electric field radiating from the human body and mutual interference. To suppress the radiation field, the frequency of the AC signal that excites the transmitter electrode must be lowered, and the sensitivity of the receiver must be raised while reducing transmission power to its minimally required level. We describe how we are developing AC electric field communication technologies to promote the further evolution of a human-area network in support of ubiquitous services, focusing on three main characteristics, enabling-transceiver technique, application-scenario modeling, and communications quality evaluation. Special attention is paid to the relationship between electro-magnetic compatibility evaluation and regulations for extremely low-power radio stations based on Japan's Radio Law.

AC Conductivity and Dielectric Properties of Borotellurite Glass

Science.gov (United States)

Taha, T. A.; Azab, A. A.

2016-10-01

Borotellurite glasses with formula 60B2O3-10ZnO-(30 - x)NaF- xTeO2 ( x = 0 mol.%, 5 mol.%, 10 mol.%, and 15 mol.%) have been synthesized by thermal melting. X-ray diffraction (XRD) analysis confirmed that the glasses were amorphous. The glass density ( ρ) was determined by the Archimedes method at room temperature. The density ( ρ) and molar volume ( V m) were found to increase with increasing TeO2 content. The direct-current (DC) conductivity was measured in the temperature range from 473 K to 623 K, in which the electrical activation energy of ionic conduction increased from 0.27 eV to 0.48 eV with increasing TeO2 content from 0 mol.% to 15 mol.%. The dielectric parameters and alternating-current (AC) conductivity ( σ ac) were investigated in the frequency range from 1 kHz to 1 MHz and temperature range from 300 K to 633 K. The AC conductivity and dielectric constant decreased with increasing TeO2 content from 0 mol.% to 15 mol.%.

Comprehensive benchmarking reveals H2BK20 acetylation as a distinctive signature of cell-state-specific enhancers and promoters.

Science.gov (United States)

Kumar, Vibhor; Rayan, Nirmala Arul; Muratani, Masafumi; Lim, Stefan; Elanggovan, Bavani; Xin, Lixia; Lu, Tess; Makhija, Harshyaa; Poschmann, Jeremie; Lufkin, Thomas; Ng, Huck Hui; Prabhakar, Shyam

2016-05-01

Although over 35 different histone acetylation marks have been described, the overwhelming majority of regulatory genomics studies focus exclusively on H3K27ac and H3K9ac. In order to identify novel epigenomic traits of regulatory elements, we constructed a benchmark set of validated enhancers by performing 140 enhancer assays in human T cells. We tested 40 chromatin signatures on this unbiased enhancer set and identified H2BK20ac, a little-studied histone modification, as the most predictive mark of active enhancers. Notably, we detected a novel class of functionally distinct enhancers enriched in H2BK20ac but lacking H3K27ac, which was present in all examined cell lines and also in embryonic forebrain tissue. H2BK20ac was also unique in highlighting cell-type-specific promoters. In contrast, other acetylation marks were present in all active promoters, regardless of cell-type specificity. In stimulated microglial cells, H2BK20ac was more correlated with cell-state-specific expression changes than H3K27ac, with TGF-beta signaling decoupling the two acetylation marks at a subset of regulatory elements. In summary, our study reveals a previously unknown connection between histone acetylation and cell-type-specific gene regulation and indicates that H2BK20ac profiling can be used to uncover new dimensions of gene regulation. © 2016 Kumar et al.; Published by Cold Spring Harbor Laboratory Press.

Survey of French spine surgeons reveals significant variability in spine trauma practices in 2013.

Science.gov (United States)

Lonjon, G; Grelat, M; Dhenin, A; Dauzac, C; Lonjon, N; Kepler, C K; Vaccaro, A R

2015-02-01

In France, attempts to define common ground during spine surgery meetings have revealed significant variability in clinical practices across different schools of surgery and the two specialities involved in spine surgery, namely, neurosurgery and orthopaedic surgery. To objectively characterise this variability by performing a survey based on a fictitious spine trauma case. Our working hypothesis was that significant variability existed in trauma practices and that this variability was related to a lack of strong scientific evidence in spine trauma care. We performed a cross-sectional survey based on a clinical vignette describing a 31-year-old male with an L1 burst fracture and neurologic symptoms (numbness). Surgeons received the vignette and a 14-item questionnaire on the management of this patient. For each question, surgeons had to choose among five possible answers. Differences in answers across surgeons were assessed using the Index of Qualitative Variability (IQV), in which 0 indicates no variability and 1 maximal variability. Surgeons also received a questionnaire about their demographics and surgical experience. Of 405 invited spine surgeons, 200 responded to the survey. Five questions had an IQV greater than 0.9, seven an IQV between 0.5 and 0.9, and two an IQV lower than 0.5. Variability was greatest about the need for MRI (IQV=0.93), degree of urgency (IQV=0.93), need for fusion (IQV=0.92), need for post-operative bracing (IQV=0.91), and routine removal of instrumentation (IQV=0.94). Variability was lowest for questions about the need for surgery (IQV=0.42) and use of the posterior approach (IQV=0.36). Answers were influenced by surgeon specialty, age, experience level, and type of centre. Clinical practice regarding spine trauma varies widely in France. Little published evidence is available on which to base recommendations that would diminish this variability. Copyright © 2015. Published by Elsevier Masson SAS.

Space Charge Modulated Electrical Breakdown of Oil Impregnated Paper Insulation Subjected to AC-DC Combined Voltages

Directory of Open Access Journals (Sweden)

Yuanwei Zhu

2018-06-01

Full Text Available Based on the existing acknowledgment that space charge modulates AC and DC breakdown of insulating materials, this investigation promotes the related investigation into the situations of more complex electrical stress, i.e., AC-DC combined voltages. Experimentally, the AC-DC breakdown characteristics of oil impregnated paper insulation were systematically investigated. The effects of pre-applied voltage waveform, AC component ratio, and sample thickness on AC-DC breakdown characteristics were analyzed. After that, based on an improved bipolar charge transport model, the space charge profiles and the space charge induced electric field distortion during AC-DC breakdown were numerically simulated to explain the differences in breakdown characteristics between the pre-applied AC and pre-applied DC methods under AC-DC combined voltages. It is concluded that large amounts of homo-charges are accumulated during AC-DC breakdown, which results in significantly distorted inner electric field, leading to variations of breakdown characteristics of oil impregnated paper insulation. Therefore, space charges under AC-DC combined voltages must be considered in the design of converter transformers. In addition, this investigation could provide supporting breakdown data for insulation design of converter transformers and could promote better understanding on the breakdown mechanism of insulating materials subjected to AC-DC combined voltages.

Induced AC voltages on pipelines may present a serious hazard

International Nuclear Information System (INIS)

Kirkpatrick, E.L.

1997-01-01

The problem of induced AC voltages on pipelines has always been with us. Early pipeline construction consisted of bare steel or cast iron pipe, which was very well grounded. Bell and spigot, mechanical, or dresser-style joint couplings often were used, creating electrically discontinuous pipelines which are less susceptible to AC induction. Although induced AC affects any pipeline parallel to a high-voltage alternating current (HVAC) power line, the effects were not noticeable on bare pipelines. With the advent of welded steel pipelines, modern cathodic protection (CP) methods and materials, and the vastly improved quality of protective coatings, induced AC effects on pipelines have become a significant consideration on many pipeline rights-of-way. In the last two to three decades, one has been seeing much more joint occupancy of the same right-of-way by one or more pipelines and power lines. As the cost of right-of-way and the difficulty in acquisition, particularly in urban areas, have risen, the concept of joint occupancy rights-of-way has become more attractive to many utility companies. Federal and state regulations usually insist on joint-use right-of-way when a utility proposes crossing regulated or publicly owned lands, wherever there is an existing easement. Such joint use allows the induced AC phenomena to occur and may create electrical hazards and interference to pipeline facilities. Underground pipelines are especially susceptible if they are well-coated and electrically isolated for CP

System and Battery Charge Control for PV-Powered AC Lighting Systems

Energy Technology Data Exchange (ETDEWEB)

Kern, G.

1999-04-01

This report reviews a number of issues specific to stand-alone AC lighting systems. A review of AC lighting technology is presented, which discusses the advantages and disadvantages of various lamps. The best lamps for small lighting systems are compact fluorescent. The best lamps for intermediate-size systems are high- or low-pressure sodium. Specifications for battery charging and load control are provided with the goal of achieving lamp lifetimes on the order of 16,000 to 24,000 hours and battery lifetimes of 4 to 5 years. A rough estimate of the potential domestic and global markets for stand-alone AC lighting systems is presented. DC current injection tests were performed on high-pressure sodium lamps and the test results are presented. Finally, a prototype system was designed and a prototype system controller (with battery charger and DC/AC inverter) was developed and built.

Photovoltaic system with improved AC connections and method of making same

Energy Technology Data Exchange (ETDEWEB)

Cioffi, Philip Michael; Todorovic, Maja Harfman; Herzog, Michael Scott; Korman, Charles Steven; Doherty, Donald M.; Johnson, Neil Anthony

2018-02-13

An alternating current (AC) harness for a photovoltaic (PV) system includes a wire assembly having a first end and a second end, the wire assembly having a plurality of lead wires, and at least one AC connection module positioned at a location along a length of the wire assembly between the first end and the second end. Further, the at least one AC connection module includes a first connection terminal electrically coupled to the plurality of lead wires of the wire assembly and constructed to electrically couple the wire assembly with an output of a first PV module of the PV system. The at least one AC connection module also includes a second connection terminal electrically coupled to the plurality of lead wires of the wire assembly and constructed to electrically couple the wire assembly with an output of a second PV module of the PV system.

A decomposition method for network-constrained unit commitment with AC power flow constraints

International Nuclear Information System (INIS)

Bai, Yang; Zhong, Haiwang; Xia, Qing; Kang, Chongqing; Xie, Le

2015-01-01

To meet the increasingly high requirement of smart grid operations, considering AC power flow constraints in the NCUC (network-constrained unit commitment) is of great significance in terms of both security and economy. This paper proposes a decomposition method to solve NCUC with AC power flow constraints. With conic approximations of the AC power flow equations, the master problem is formulated as a MISOCP (mixed integer second-order cone programming) model. The key advantage of this model is that the active power and reactive power are co-optimised, and the transmission losses are considered. With the AC optimal power flow model, the AC feasibility of the UC result of the master problem is checked in subproblems. If infeasibility is detected, feedback constraints are generated based on the sensitivity of bus voltages to a change in the unit reactive power generation. They are then introduced into the master problem in the next iteration until all AC violations are eliminated. A 6-bus system, a modified IEEE 30-bus system and the IEEE 118-bus system are used to validate the performance of the proposed method, which provides a satisfactory solution with approximately 44-fold greater computational efficiency. - Highlights: • A decomposition method is proposed to solve the NCUC with AC power flow constraints • The master problem considers active power, reactive power and transmission losses. • OPF-based subproblems check the AC feasibility using parallel computing techniques. • An effective feedback constraint interacts between the master problem and subproblem. • Computational efficiency is significantly improved with satisfactory accuracy

Electrical actuation of electrically conducting and insulating droplets using ac and dc voltages

International Nuclear Information System (INIS)

Kumari, N; Bahadur, V; Garimella, S V

2008-01-01

Electrical actuation of liquid droplets at the microscale offers promising applications in the fields of microfluidics and lab-on-chip devices. Much prior research has targeted the electrical actuation of electrically conducting liquid droplets using dc voltages (classical electrowetting). Electrical actuation of conducting droplets using ac voltages and the actuation of insulating droplets (using dc or ac voltages) has remained relatively unexplored. This paper utilizes an energy-minimization-based analytical framework to study the electrical actuation of a liquid droplet (electrically conducting or insulating) under ac actuation. It is shown that the electromechanical regimes of classical electrowetting, electrowetting under ac actuation and insulating droplet actuation can be extracted from the generic electromechanical actuation framework, depending on the electrical properties of the droplet, the underlying dielectric layer and the frequency of the actuation voltage. This paper also presents experiments which quantify the influence of the ac frequency and the electrical properties of the droplet on its velocity under electrical actuation. The velocities of droplets moving between two parallel plates under ac actuation are experimentally measured; these velocities are then related to the actuation force on the droplet which is predicted by the electromechanical model developed in this work. It is seen that the droplet velocities are strongly dependent on the frequency of the ac actuation voltage; the cut-off ac frequency, above which the droplet fails to actuate, is experimentally determined and related to the electrical conductivity of the liquid. This paper then analyzes and directly compares the various electromechanical regimes for the actuation of droplets in microfluidic applications

Calorimetric method of ac loss measurement in a rotating magnetic field

Energy Technology Data Exchange (ETDEWEB)

Ghoshal, P. K. [Oxford Instruments NanoScience, Abingdon, Oxfordshire OX13 5QX (United Kingdom); Coombs, T. A.; Campbell, A. M. [Department of Engineering, Electrical Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

2010-07-15

A method is described for calorimetric ac-loss measurements of high-T{sub c} superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

Bees for development: Brazilian survey reveals how to optimize stingless beekeeping.

Science.gov (United States)

Jaffé, Rodolfo; Pope, Nathaniel; Torres Carvalho, Airton; Madureira Maia, Ulysses; Blochtein, Betina; de Carvalho, Carlos Alfredo Lopes; Carvalho-Zilse, Gislene Almeida; Freitas, Breno Magalhães; Menezes, Cristiano; Ribeiro, Márcia de Fátima; Venturieri, Giorgio Cristino; Imperatriz-Fonseca, Vera Lucia

2015-01-01

Stingless bees are an important asset to assure plant biodiversity in many natural ecosystems, and fulfill the growing agricultural demand for pollination. However, across developing countries stingless beekeeping remains an essentially informal activity, technical knowledge is scarce, and management practices lack standardization. Here we profited from the large diversity of stingless beekeepers found in Brazil to assess the impact of particular management practices on productivity and economic revenues from the commercialization of stingless bee products. Our study represents the first large-scale effort aiming at optimizing stingless beekeeping for honey/colony production based on quantitative data. Survey data from 251 beekeepers scattered across 20 Brazilian States revealed the influence of specific management practices and other confounding factors over productivity and income indicators. Specifically, our results highlight the importance of teaching beekeepers how to inspect and feed their colonies, how to multiply them and keep track of genetic lineages, how to harvest and preserve the honey, how to use vinegar traps to control infestation by parasitic flies, and how to add value by labeling honey containers. Furthermore, beekeeping experience and the network of known beekeepers were found to be key factors influencing productivity and income. Our work provides clear guidelines to optimize stingless beekeeping and help transform the activity into a powerful tool for sustainable development.

Antifriction coatings based on a-C for biomedicine applications

International Nuclear Information System (INIS)

Yurjev, Y N; Kiseleva, D V; Zaitcev, D A; Sidelev, D V; Korneva, O S

2016-01-01

This article reports on the investigation of mechanical properties of carbon films deposited by dual magnetron sputtering system with closed and mirror magnetic field. There is shown that a-C films with predominantly sp 2 -phase have relatively high hardness (up to 20 GPa) and low friction index (∼0.01). The influence of magnetic field on friction index is determined. The analysis of experimental data shows the obtained a-C samples can be used for biomedicine applications. (paper)

AC magnetic losses in Bi-2223/Ag tapes with different aspect ratios

Energy Technology Data Exchange (ETDEWEB)

Fang, J.; Luo, X.M.; Chen, D.X.; Collings, E.W.; Lee, E.; Sumption, M.D.; Alamgir, A.K.M.; Yi, H.P.; Fang, J.G.; Gu, C.; Guo, S.Q.; Liu, M.L.; Xin, Y.; Han, Z

2004-10-01

AC losses in multi-filamentary tapes depend on various parameters. Among them, the overall tape width and thickness are expected to have an important influence. In order to study this geometrical effect, five Bi-2223/Ag tapes with different aspect ratios from 5 to 26 have been prepared. AC losses have been measured at 77 K when a perpendicular AC magnetic field is applied. It has been found that at any frequencies the magnetic loss per cycle increases as the aspect ratio increases. For AC magnetic loss, with increasing frequency from 3 to 9000 Hz the losses as a function of frequency show a maximum if the field amplitude is much less than the full penetration field or increase continuously if the field amplitude is larger.

AC magnetic losses in Bi-2223/Ag tapes with different aspect ratios

International Nuclear Information System (INIS)

Fang, J.; Luo, X.M.; Chen, D.X.; Collings, E.W.; Lee, E.; Sumption, M.D.; Alamgir, A.K.M.; Yi, H.P.; Fang, J.G.; Gu, C.; Guo, S.Q.; Liu, M.L.; Xin, Y.; Han, Z.

2004-01-01

AC losses in multi-filamentary tapes depend on various parameters. Among them, the overall tape width and thickness are expected to have an important influence. In order to study this geometrical effect, five Bi-2223/Ag tapes with different aspect ratios from 5 to 26 have been prepared. AC losses have been measured at 77 K when a perpendicular AC magnetic field is applied. It has been found that at any frequencies the magnetic loss per cycle increases as the aspect ratio increases. For AC magnetic loss, with increasing frequency from 3 to 9000 Hz the losses as a function of frequency show a maximum if the field amplitude is much less than the full penetration field or increase continuously if the field amplitude is larger

Healthcare provider-led interventions to support medication adherence following ACS: a meta-analysis.

Science.gov (United States)

Crawshaw, Jacob; Auyeung, Vivian; Ashworth, Lucy; Norton, Sam; Weinman, John

2017-01-01

We conducted a systematic review and meta-analysis to determine the effectiveness of healthcare provider-led (HCPs) interventions to support medication adherence in patients with acute coronary syndrome (ACS). A systematic search of Cochrane Library, Medline, EMBASE, PsycINFO, Web of Science, IPA, CINAHL, ASSIA, OpenGrey, EthOS, WorldCat and PQDT was undertaken. Interventions were deemed eligible if they included adult ACS patients, were HCP-led, measured medication adherence and randomised participants to parallel groups. Intervention content was coded using the Behaviour Change Technique (BCT) Taxonomy and data were pooled for analysis using random-effects models. Our search identified 8870 records, of which 27 were eligible (23 primary studies). A meta-analysis (n=9735) revealed HCP-led interventions increased the odds of medication adherence by 54% compared to control interventions (k=23, OR 1.54, 95% CI 1.26 to 1.88, I 2 =57.5%). After removing outliers, there was a 41% increase in the odds of medication adherence with moderate heterogeneity (k=21, OR 1.41, 95% CI 1.21 to 1.65, I 2 =35.3%). Interventions that included phone contact yielded (k=12, OR 1.63, 95% CI 1.25 to 2.12, I 2 =32.0%) a larger effect compared to those delivered exclusively in person. A total of 32/93 BCTs were identified across interventions (mean=4.7, SD=2.2) with 'information about health consequences' (BCT 5.1) (19/23) the most common. HCP-led interventions for ACS patients appear to have a small positive impact on medication adherence. While we were able to identify BCTs among interventions, data were insufficient to determine the impact of particular BCTs on study effectiveness. CRD42016037706.

Study of the electric Held in HTS tape caused by perpendicular AC magnetic field

International Nuclear Information System (INIS)

Roiberg, V; Kopansky, F.

2004-01-01

Full Text: In a previous work we studied the influence of AC magnetic fields on voltage-currents (V-I) characteristics of high temperature superconducting (HTS) multi filament BSCC0-2223 tapes. It was found that AC magnetic fields perpendicular to the ab plane (the wide surface of the tape) cause a linear decrease of the critical current (IC) with amplitude of the AC magnetic field. The degradation of IC in .AC field was explained by the geometrical model according to which the transport current floe: is confined to the central zone of the tape where .AC field does not penetrate. For deeper understanding of the observed phenomena we carried out a study of the time dependence of the electric field during the cycle of AC field. At the same time we expanded the frequency range to low frequencies down to 1 Hz. The main results of the work are as following. 1. The time modulation of the electric field E in the HTS tape carrying transport DC current has the double frequency relating to AC magnetic field. 2. In field amplitudes less than 70 G the electric field modulation decreases with increasing frequency in opposite to its well-pronounced increase in higher AC field amplitudes. Alcove 70 G, the electric field increases with increasing the frequency of the external magnetic field. The wave forms of the electric field are different in both amplitudes ranges. 3. E-I curves of the tape in low amplitudes are frequency independent and coincide with E-l curves in AC field with intensity equal to the AC field amplitude. 4. In high AC field amplitudes, a strong dependence of the E-I curves on frequency is observed in the frequency range of 1-40 Hz and no dependence is observed in higher frequencies. Our results suggest that a combination of the geometrical model with flux creep concepts is necessary for a better understanding of the electric field behavior in our measurement conditions

Modelling and measurement of ac loss in BSCCO/Ag-tape windings

International Nuclear Information System (INIS)

Oomen, M P; Nanke, R; Leghissa, M

2003-01-01

High-temperature superconducting (HTS) transformers promise decreased weight and volume and higher efficiency. A 1 MVA HTS railway transformer was built and tested at Siemens AG. This paper deals with the prediction of ac loss in the BSCCO/Ag-tape windings. In a railway transformer the tape carries ac current in alternating field, the temperature differs from 77 K, tapes are stacked or cabled and overcurrents and higher harmonics occur. In ac-loss literature these issues are treated separately, if at all. We have developed a model that predicts the ac loss in sets of BSCCO/Ag-tape coils, and deals with the above-mentioned issues. The effect of higher harmonics on the loss in HTS tapes is considered for the first time. The paper gives a complete overview of the model equations and required input parameters. The model is validated over a wide range of the input parameters, using the measured critical current and ac loss of single tapes, single coils and sets of coils in the 1 MVA transformer. An accuracy of around 25% is achieved in all relevant cases. Presently the model is developed further, in order to describe other HTS materials and other types of applications

AC Loss Reduction in Filamentized YBCO Coated Conductors with Virtual Transverse Cross-cuts

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yifei [ORNL; Duckworth, Robert C [ORNL; Ha, Tam T [ORNL; List III, Frederick Alyious [ORNL; Gouge, Michael J [ORNL; Chen, Y [SuperPower Incorporated, Schenectady, New York; X, Xiong, [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York

2011-01-01

While the performance of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO)-based coated conductors under dc currents has improved significantly in recent years, filamentization is being investigated as a technique to reduce ac loss so that the 2nd generation (2G) high temperature superconducting (HTS) wires can also be utilized in various ac power applications such as cables, transformers and fault current limiters. Experimental studies have shown that simply filamentizing the superconducting layer is not effective enough to reduce ac loss because of incomplete flux penetration in between the filaments as the length of the tape increases. To introduce flux penetration in between the filaments more uniformly and further reduce the ac loss, virtual transverse cross-cuts were made in superconducting filaments of the coated conductors fabricated using the metal organic chemical vapor deposition (MOCVD) method. The virtual transverse cross-cuts were formed by making cross-cuts (17 - 120 {micro}m wide) on the IBAD (ion beam assisted deposition)-MgO templates using laser scribing followed by depositing the superconducting layer ({approx} 0.6 {micro}m thick). AC losses were measured and compared for filamentized conductors with and without the cross-cuts under applied peak ac fields up to 100 mT. The results were analyzed to evaluate the efficacy of filament decoupling and the feasibility of using this method to achieve ac loss reduction.

HST/ACS IMAGING OF OMEGA CENTAURI: OPTICAL COUNTERPARTS OF CHANDRA X-RAY SOURCES

International Nuclear Information System (INIS)

Cool, Adrienne M.; Arias, Tersi; Brochmann, Michelle; Dorfman, Jason; Gafford, April; White, Vivian; Haggard, Daryl; Anderson, Jay

2013-01-01

We present results of a search for optical counterparts of X-ray sources in and toward the globular cluster Omega Centauri (NGC 5139) using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The ACS data consist of a mosaic of Wide Field Channel images obtained using F625W, F435W, and F658N filters; with nine pointings we cover the central ∼10' × 10' of the cluster and encompass 109 known Chandra sources. We find promising optical counterparts for 59 of the sources, ∼40 of which are likely to be associated with the cluster. These include 27 candidate cataclysmic variables (CVs), 24 of which are reported here for the first time. Fourteen of the CV candidates are very faint, with absolute magnitudes in the range M 625 =10.4-12.6, making them comparable in brightness to field CVs near the period minimum discovered in the Sloan Digital Sky Survey. Additional optical counterparts include three BY Dra candidates, a possible blue straggler, and a previously reported quiescent low-mass X-ray binary. We also identify 3 foreground stars and 11 probable active galactic nuclei. Finally, we report the discovery of a group of seven stars whose X-ray properties are suggestive of magnetically active binaries, and whose optical counterparts lie on or very near the metal-rich anomalous giant and subgiant branches in ω Cen. If the apparent association between these seven stars and the RGB/SGB-a stars is real, then the frequency of X-ray sources in this metal-rich population is enhanced by a factor of at least five relative to the other giant and subgiant populations in the cluster. If these stars are not members of the metal-rich population, then they bring the total number of red stragglers (also known as sub-subgiants) that have been identified in ω to Cen 20, the largest number yet known in any globular cluster.

HST/ACS Imaging of Omega Centauri: Optical Counterparts of Chandra X-Ray Sources

Science.gov (United States)

Cool, Adrienne M.; Haggard, Daryl; Arias, Tersi; Brochmann, Michelle; Dorfman, Jason; Gafford, April; White, Vivian; Anderson, Jay

2013-02-01

We present results of a search for optical counterparts of X-ray sources in and toward the globular cluster Omega Centauri (NGC 5139) using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The ACS data consist of a mosaic of Wide Field Channel images obtained using F625W, F435W, and F658N filters; with nine pointings we cover the central ~10' × 10' of the cluster and encompass 109 known Chandra sources. We find promising optical counterparts for 59 of the sources, ~40 of which are likely to be associated with the cluster. These include 27 candidate cataclysmic variables (CVs), 24 of which are reported here for the first time. Fourteen of the CV candidates are very faint, with absolute magnitudes in the range M 625 =10.4-12.6, making them comparable in brightness to field CVs near the period minimum discovered in the Sloan Digital Sky Survey. Additional optical counterparts include three BY Dra candidates, a possible blue straggler, and a previously reported quiescent low-mass X-ray binary. We also identify 3 foreground stars and 11 probable active galactic nuclei. Finally, we report the discovery of a group of seven stars whose X-ray properties are suggestive of magnetically active binaries, and whose optical counterparts lie on or very near the metal-rich anomalous giant and subgiant branches in ω Cen. If the apparent association between these seven stars and the RGB/SGB-a stars is real, then the frequency of X-ray sources in this metal-rich population is enhanced by a factor of at least five relative to the other giant and subgiant populations in the cluster. If these stars are not members of the metal-rich population, then they bring the total number of red stragglers (also known as sub-subgiants) that have been identified in ω to Cen 20, the largest number yet known in any globular cluster.

Transport ac losses in Bi-2223 multifilamentary tapes - conductor materials aspect

Energy Technology Data Exchange (ETDEWEB)

Glowacki, B A [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge BC2 3QZ (United Kingdom); Majoros, M [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Institute of Electrical Engineering, SAS, Bratislava (Slovakia)

2000-05-01

Transport ac losses in technical superconductors based on Bi-2223 tape material are influenced by many parameters. The major factors that define the ac performance of such conductors are the following: the size and number of filaments, their geometrical arrangement in the cross-section of the conductor, the twist pitch length, the resistivity of the matrix, the presence of oxide barriers around the filaments and deformation procedures such as sequential pressing or rolling followed by appropriate thermal treatment. In the present paper the above aspects are addressed from the viewpoint of the materials science of technical conductor design. Transport ac losses at power frequencies in different types of Bi-2223 conductor are presented and analysed. The results of conductor design analysis with respect to the coexistence of the superconductor with other materials in the conductor structure are presented. New concepts for minimization of the transport ac losses are discussed in detail. (author)

AC/DC electrical conduction and dielectric properties of PMMA/PVAc/C60 down-shifting nanocomposite films

Science.gov (United States)

El-Bashir, S. M.; Alwadai, N. M.; AlZayed, N.

2018-02-01

Polymer nanocomposite films were prepared by doping fullerene C60 in polymer blend composed of polymethacrylate/polyvinyl acetate blends (PMMA/PVAc) using solution cast technique. The films were characterized by differential scanning calorimeter (DSC), Transmission electron microscope (TEM), DC/AC electrical conductivity and dielectric measurements in the frequency range (100 Hz- 1 MHz). The glass transition temperature, Tg, was increased by increasing the concentration of fullerene C60; this property reflects the increase of thermal stability by increasing the nanofiller content. The DC and AC electrical conductivities were enhanced by increasing C60 concentration due to the electron hopping or tunneling between filled and empty localized states above Tg. The relaxation time was determined from the αβ -relaxations and found to be attenuated by increasing the temperature as a typical behavior of amorphous polymers. The calculated values of thermodynamic parameters revealed the increase of molecular stability by increasing the doping concentration; this feature supports the application of PMMA/PVAc/C60 nanocomposite films in a wide scale of solar energy conversion applications such as luminescent down-shifting (LDS) coatings for photovoltaic cells.

AC electric field assisted orientational photorefractive effect in C60-doped nematic liquid crystal

International Nuclear Information System (INIS)

Sun Xiudong; Pei Yanbo; Yao Fengfeng; Zhang Jianlong; Hou Chunfeng

2007-01-01

Photorefractive gratings were produced in a C 60 -doped nematic liquid crystal cell under the application of two coherent beams and a nonbiased sinusoidal ac electric field. The beam coupling and diffraction of the ac electric field assisted gratings were studied systematically. A stable asymmetric energy transference was obtained. Diffraction was observed when the angle (between the normal of the cell and the bisector of the writing beams) was 0 0 , and the dependence of diffraction efficiency on the peak-to-peak value of the ac voltage was similar to that at an incidence angle of 45 0 , suggesting that the role of the ac field was to facilitate the charge separation, and the space-charge field (SCF) originated predominantly from the diffusion of the ac electric field assisted photo-induced carriers under the application of nonuniform illumination and an applied ac field. The grating was produced by director reorientation induced by the cooperation of the SCF and the applied ac electric field. A self-erasing phenomenon was observed in this cell. An explanation in terms of the movement of two kinds of carriers with opposite signs was proposed

Bacillus thuringiensis delta-endotoxin Cry1Ac domain III enhances activity against Heliothis virescens in some, but not all Cry1-Cry1Ac hybrids

NARCIS (Netherlands)

Karlova, R.B.; Weemen, W.M.J.; Naimov, S.; Ceron, J.; Dukiandjiev, S.; Maagd, de R.A.

2005-01-01

We investigated the role of domain III of Bacillus thuringiensis d-endotoxin Cry1Ac in determining toxicity against Heliothis virescens. Hybrid toxins, containing domain III of Cry1Ac with domains I and II of Cry1Ba, Cry1Ca, Cry1Da, Cry1Ea, and Cry1Fb, respectively, were created. In this way Cry1Ca,

Update History of This Database - AcEST | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ...List Contact us AcEST Update History of This Database Date Update contents 2013/01/10 Errors found on AcEST ...s Database Database Description Download License Update History of This Data...base Site Policy | Contact Us Update History of This Database - AcEST | LSDB Archive ... ...Conting data have been correceted. For details, please refer to the following page. Data correction 2010/03/29 AcEST English archi

Design and implementation of co-operative control strategy for hybrid AC/DC microgrids

Science.gov (United States)

Mahmud, Rasel

This thesis is mainly divided in two major sections: 1) Modeling and control of AC microgrid, DC microgrid, Hybrid AC/DC microgrid using distributed co-operative control, and 2) Development of a four bus laboratory prototype of an AC microgrid system. At first, a distributed cooperative control (DCC) for a DC microgrid considering the state-of-charge (SoC) of the batteries in a typical plug-in-electric-vehicle (PEV) is developed. In DC microgrids, this methodology is developed to assist the load sharing amongst the distributed generation units (DGs), according to their ratings with improved voltage regulation. Subsequently, a DCC based control algorithm for AC microgrid is also investigated to improve the performance of AC microgrid in terms of power sharing among the DGs, voltage regulation and frequency deviation. The results validate the advantages of the proposed methodology as compared to traditional droop control of AC microgrid. The DCC-based control methodology for AC microgrid and DC microgrid are further expanded to develop a DCC-based power management algorithm for hybrid AC/DC microgrid. The developed algorithm for hybrid microgrid controls the power flow through the interfacing converter (IC) between the AC and DC microgrids. This will facilitate the power sharing between the DGs according to their power ratings. Moreover, it enables the fixed scheduled power delivery at different operating conditions, while maintaining good voltage regulation and improved frequency profile. The second section provides a detailed explanation and step-by-step design and development of an AC/DC microgrid testbed. Controllers for the three-phase inverters are designed and tested on different generation units along with their corresponding inductor-capacitor-inductor (LCL) filters to eliminate the switching frequency harmonics. Electric power distribution line models are developed to form the microgrid network topology. Voltage and current sensors are placed in the proper

Stretched exponential relaxation and ac universality in disordered dielectrics

DEFF Research Database (Denmark)

Milovanov, Alexander V.; Rypdal, Kristoffer; Juul Rasmussen, Jens

2007-01-01

This paper is concerned with the connection between the properties of dielectric relaxation and alternating-current (ac) conduction in disordered dielectrics. The discussion is divided between the classical linear-response theory and a self-consistent dynamical modeling. The key issues are stretc......This paper is concerned with the connection between the properties of dielectric relaxation and alternating-current (ac) conduction in disordered dielectrics. The discussion is divided between the classical linear-response theory and a self-consistent dynamical modeling. The key issues...

Antibacterial Ag/a-C nanocomposite coatings: The influence of nano-galvanic a-C and Ag couples on Ag ionization rates

Energy Technology Data Exchange (ETDEWEB)

Manninen, N.K., E-mail: nora.sousa@dem.uc.pt [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra (Portugal); GRF-CFUM, Physics Department, University of Minho, Campus of Azurém, 4800-058 Guimarães (Portugal); Calderon, S. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra (Portugal); GRF-CFUM, Physics Department, University of Minho, Campus of Azurém, 4800-058 Guimarães (Portugal); Carvalho, I. [GRF-CFUM, Physics Department, University of Minho, Campus of Azurém, 4800-058 Guimarães (Portugal); CEB—Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga (Portugal); Henriques, M. [CEB—Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga (Portugal); Cavaleiro, A. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra (Portugal); Carvalho, S. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra (Portugal); GRF-CFUM, Physics Department, University of Minho, Campus of Azurém, 4800-058 Guimarães (Portugal)

2016-07-30

Highlights: • Amorphous carbon (a-C), Ag/a-C and Ag coatings were deposited by magnetron sputtering. • a-C/Ag coating shows antibacterial activity against S. epidermidis. • The formation of nano-galvanic couples in a-C/Ag enhances the Ag{sup +} ionization rate. • The Ag{sup +} ionization occurs along with Ag nanoparticles agglomeration in 0.9% NaCl. - Abstract: Biofilm formation has been pointed as a major concern in different industrial applications, namely on biomedical implants and surgical instruments, which has prompted the development of new strategies for production of efficient antimicrobial surfaces. In this work, nano-galvanic couples were created to enhance the antibacterial properties of silver, by embedding it into amorphous carbon (a-C) matrix. The developed Ag/a-C nanocomposite coatings, deposited by magnetron sputtering, revealed an outstanding antibacterial activity against Staphylococcus epidermidis, promoting a total reduction in biofilm formation with no bacteria counts in all dilution. The open circuit potential (OCP) tests in 0.9% NaCl confirmed that a-C shows a positive OCP value, in contrast to Ag coating, thus enhancing the ionization of biocidal Ag{sup +} due to the nano-galvanic couple activation. This result was confirmed by the inductively coupled plasma-optical emission spectroscopy (ICP-OES), which revealed a higher Ag ionization rate in the nanocomposite coating in comparison with the Ag coating. The surface of Ag/a-C and Ag coatings immersed in 0.9% NaCl were monitored by scanning electron microscopy (SEM) over a period of 24 h, being found that the Ag ionization determined by ICP-OES was accompanied by an Ag nanoparticles coalescence and agglomeration in Ag/a-C coating.

Measuring Gravitational Flexion in ACS Clusters

Science.gov (United States)

Goldberg, David

2005-07-01

We propose measurement of the gravitational "Flexion" signal in ACS cluster images. The flexion, or "arciness" of a lensed background galaxy arises from variations in the lensing field. As a result, it is extremely sensitive to small scale perturbations in the field, and thus, to substructure in clusters. Moreover, because flexion represents gravitationally induced asymmetries in the lensed image, it is completely separable from traditional measurements of shear, which focus on the induced ellipticity of the image, and thus, the two signals may be extracted simultaneously. Since typical galaxies are roughly symmetric upon 180 degree rotation, even a small induced flexion can potentially produce a noticeable effect {Goldberg & Bacon, 2005}. We propose the measurement of substructure within approximately 4 clusters with high-quality ACS data, and will further apply a test of a new tomographic technique whereby comparisons of lensed arcs at different redshifts may be used to estimate the background cosmology, and thus place constraints on the equation of state of dark energy.

Controlled formation of metallic nanowires via Au nanoparticle ac trapping

International Nuclear Information System (INIS)

Bernard, L; Calame, M; Molen, S J van der; Liao, J; Schoenenberger, C

2007-01-01

Applying ac voltages, we trapped gold nanoparticles between micro-fabricated electrodes under well-defined conditions. We demonstrate that the nanoparticles can be controllably fused together to form homogeneous gold nanowires with pre-defined diameters and conductance values. Whereas electromigration is known to form a gap when a dc voltage is applied, this ac technique achieves the opposite, thereby completing the toolkit for the fabrication of nanoscale junctions

Controlled formation of metallic nanowires via Au nanoparticle ac trapping

Energy Technology Data Exchange (ETDEWEB)

Bernard, L; Calame, M; Molen, S J van der; Liao, J; Schoenenberger, C [Institute of Physics, University of Basel, CH-4056 Basel (Switzerland)

2007-06-13

Applying ac voltages, we trapped gold nanoparticles between micro-fabricated electrodes under well-defined conditions. We demonstrate that the nanoparticles can be controllably fused together to form homogeneous gold nanowires with pre-defined diameters and conductance values. Whereas electromigration is known to form a gap when a dc voltage is applied, this ac technique achieves the opposite, thereby completing the toolkit for the fabrication of nanoscale junctions.

Influences of Cry1Ac broccoli on larval survival and oviposition of diamondback moth.

Science.gov (United States)

Yi, Dengxia; Cui, Shusong; Yang, Limei; Fang, Zhiyuan; Liu, Yumei; Zhuang, Mu; Zhang, Yangyong

2015-01-01

Larval survival and oviposition behavior of three genotypes of diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), (homozygous Cry1Ac-susceptibile, Cry1Ac-resistant, and their F1 hybrids), on transgenic Bacillus thuringiensis (Bt) broccoli expressing different levels of Cry1Ac protein were evaluated in laboratory. These Bt broccoli lines were designated as relative low, medium, and high, respectively, according to the Cry1Ac content. Untransformed brocccoli plants were used as control. Larval survival of diamondback moth on non-Bt leaves was not significantly different among the three genotypes. The Cry1Ac-resistant larvae could survive on the low level of Bt broccoli plants, while Cry1Ac-susceptible and F1 larvae could not survive on them. The three genotypes of P. xylostella larvae could not survive on medium and high levels of Bt broccoli. In oviposition choice tests, there was no significant difference in the number of eggs laid by the three P. xylostella genotypes among different Bt broccoli plants. The development of Cry1Ac-susceptible and Cry1Ac-resistant P. xylostella on intact Bt plants was also tested in greenhouse. All susceptible P. xylostella larvae died on all Bt plants, while resistant larvae could survive on broccoli, which expresses low Cry1Ac protein under greenhouse conditions. The results of the greenhouse trials were similar to that of laboratory tests. This study indicated that high dose of Bt toxins in broccoli cultivars or germplasm lines is required for effective resistance management. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Low AC Loss YBCO Coated Conductor Geometry by Direct Inkjet Printing

Energy Technology Data Exchange (ETDEWEB)

Rupich, Martin, Dr. [American Superconductor Corporation; Duckworth, Robert, Dr. [Oak Ridge National Laboratory

2009-10-01

The second generation (2G) high temperature superconductors (HTS) wire offers potential benefits for many electric power applications, including ones requiring filamentized conductors with low ac loss, such as transformers and fault current limiters. However, the use of 2G wire in these applications requires the development of both novel multi-filamentary conductor designs with lower ac losses and the development of advanced manufacturing technologies that enable the low-cost manufacturing of these filamentized architectures. This Phase I SBIR project focused on testing inkjet printing as a potential low-cost, roll-to-roll manufacturing technique to fabricate potential low ac loss filamentized architectures directly on the 2G template strips.

The ACS-NUCL Division 50th Anniversary: Introduction

Energy Technology Data Exchange (ETDEWEB)

Hobart, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-01-10

The ACS Division of Nuclear Chemistry and Technology was initiated in 1955 as a subdivision of the Division of Industrial and Engineering Chemistry. Probationary divisional status was lifted in 1965. The Division’s first symposium was held in Denver in 1964 and it is fitting that we kicked-off the 50th Anniversary in Denver in the spring of 2015. Listed as a small ACS Division with only about 1,000 members, NUCL’s impact over the past fifty years has been remarkable. National ACS meetings have had many symposia sponsored or cosponsored by NUCL that included Nobel Laureates, U.S. Senators, other high-ranking officials and many students as speakers. The range of subjects has been exceptional as are the various prestigious awards established by the Division. Of major impact has been the past 30 years of the NUCL Nuclear Chemistry Summer Schools to help fill the void of qualified nuclear scientists and technicians. In celebrating the 50th Anniversary we honor the past, celebrate the present and shape the future of the Division and nuclear science and technology. To celebrate this auspicious occasion a commemorative lapel pin has been designed for distribution to NUCL Division members.

A Cloud-Based Scavenger Hunt: Orienting Undergraduates to ACS National Meetings

Science.gov (United States)

Kubasik, Matthew A.; Van Dyke, Aaron R.; Harper-Leatherman, Amanda S.; Miecznikowski, John R.; Steffen, L. Kraig; Smith-Carpenter, Jillian

2016-01-01

American Chemical Society (ACS) National Meetings are valuable for the development of undergraduate researchers but can be overwhelming for first-time attendees. To orient and engage students with the range of offerings at an ACS meeting, we developed a cloud-based scavenger hunt. Using their mobile devices, teams of undergraduates…

On the Application of TLS Techniques to AC Electrical Drives

Directory of Open Access Journals (Sweden)

M. Cirrincione

2005-03-01

Full Text Available This paper deals with the application of a new neuron, the TLS EXIN neuron, to AC induction motor drives. In particular, it addresses two important subjects of AC induction motor drives: the on-line estimation of the electrical parameters of the machine and the speed estimation in sensorless drives. On this basis, this work summarizes the parameter estimation and sensorless techniques already developed by the authors over these last few years, all based on the TLS EXIN. With regard to sensorless, two techniques are proposed: one based on the MRAS and the other based on the full-order Luenberger observer. The work show some of the most significant results obtained by the authors in these fields and stresses the important potentiality of this new neural technique in AC induction machine drives.

Reliability of emergency ac power systems at nuclear power plants

International Nuclear Information System (INIS)

Battle, R.E.; Campbell, D.J.

1983-07-01

Reliability of emergency onsite ac power systems at nuclear power plants has been questioned within the Nuclear Regulatory Commission (NRC) because of the number of diesel generator failures reported by nuclear plant licensees and the reactor core damage that could result from diesel failure during an emergency. This report contains the results of a reliability analysis of the onsite ac power system, and it uses the results of a separate analysis of offsite power systems to calculate the expected frequency of station blackout. Included is a design and operating experience review. Eighteen plants representative of typical onsite ac power systems and ten generic designs were selected to be modeled by fault trees. Operating experience data were collected from the NRC files and from nuclear plant licensee responses to a questionnaire sent out for this project

AC losses and stability on large cable-in-conduit superconductors

Science.gov (United States)

Bruzzone, Pierluigi

1998-12-01

The cable-in-conduit superconductors are preferred for applications where the AC losses and stability are a major concern, e.g., fusion magnets and SMES. A review of coupling currents loss results for both NbTi and Nb 3Sn cable-in-conduit conductors (CICC) is presented and the AC loss relevant features are listed, with special emphasis for the role of the interstrand resistance and strand coating. The transient stability approach for CICCs is discussed and the analytical models are quoted as well as the relevant experimental database. The likely spectrum of transient disturbance in CICC is reviewed and the need to account for interstrand current sharing in the design is outlined. Eventually a practical criterion for the interstrand resistance is proposed to link the stability and AC loss design.

N-Doped Dual Carbon-Confined 3D Architecture rGO/Fe3O4/AC Nanocomposite for High-Performance Lithium-Ion Batteries.

Science.gov (United States)

Ding, Ranran; Zhang, Jie; Qi, Jie; Li, Zhenhua; Wang, Chengyang; Chen, Mingming

2018-04-25

To address the issues of low electrical conductivity, sluggish lithiation kinetics and dramatic volume variation in Fe 3 O 4 anodes of lithium ion battery, herein, a double carbon-confined three-dimensional (3D) nanocomposite architecture was synthesized by an electrostatically assisted self-assembly strategy. In the constructed architecture, the ultrafine Fe 3 O 4 subunits (∼10 nm) self-organize to form nanospheres (NSs) that are fully coated by amorphous carbon (AC), formatting core-shell structural Fe 3 O 4 /AC NSs. By further encapsulation by reduced graphene oxide (rGO) layers, a constructed 3D architecture was built as dual carbon-confined rGO/Fe 3 O 4 /AC. Such structure restrains the adverse reaction of the electrolyte, improves the electronic conductivity and buffers the mechanical stress of the entire electrode, thus performing excellent long-term cycling stability (99.4% capacity retention after 465 cycles relevant to the second cycle at 5 A g -1 ). Kinetic analysis reveals that a dual lithium storage mechanism including a diffusion reaction mechanism and a surface capacitive behavior mechanism coexists in the composites. Consequently, the resulting rGO/Fe 3 O 4 /AC nanocomposite delivers a high reversible capacity (835.8 mA h g -1 for 300 cycles at 1 A g -1 ), as well as remarkable rate capability (436.7 mA h g -1 at 10 A g -1 ).

Dielectric response and ac conductivity analysis of hafnium oxide nanopowder

International Nuclear Information System (INIS)

Karahaliou, P K; Xanthopoulos, N; Krontiras, C A; Georga, S N

2012-01-01

The dielectric response of hafnium oxide nanopowder was studied in the frequency range of 10 -2 -10 6 MHz and in the temperature range of 20-180 °C. Broadband dielectric spectroscopy was applied and the experimental results were analyzed and discussed using the electric modulus (M*) and alternating current (ac) conductivity formalisms. The analyses of the dc conductivity and electric modulus data revealed the presence of mechanisms which are thermally activated, both with almost the same activation energy of 1.01 eV. A fitting procedure involving the superposition of the thermally activated dc conductivity, the universal dielectric responce and the near constant loss terms has been used to describe the frequency evolution of the real part of the specific electrical conductivity. The conductivity master curve was obtained, suggesting that the time-temperature superposition principle applies for the studied system, thus implying that the conductivity mechanisms are temperature independent.

Development of AC-DC power system simulator

International Nuclear Information System (INIS)

Ichikawa, Tatsumi; Ueda, Kiyotaka; Inoue, Toshio

1984-01-01

A modeling and realization technique is described for realtime plant dynamics simulation of nuclear power generating unit in AC-DC power system simulator. Dynamic behavior of reactor system and steam system is important for investigation a further adequate unit control and protection system to system faults in AC and DC power system. Each unit of two nuclear power generating unit in the power system simulator consists of micro generator, DC motors, flywheels and process computer. The DC motor and flywheel simulates dynamic characteristics of steam turbine, and process computer simulates plant dynamics by digital simulation. We have realized real-time plant dynamics simulation by utilizing a high speed process I/O and a high speed digital differential analyzing processor (DDA) in which we builted a newly developed simple plant model. (author)

Three-Phase Multistage System (DC-AC-DC-AC for Connecting Solar Cells to the Grid

Directory of Open Access Journals (Sweden)

Mahmudreza Changizian

2017-11-01

Full Text Available Inverter systems that feed electrical power from photovoltaic (PV system into the grid must convert the direct current of the PV array into the alternating current of the grid. In many applications, it is important for a converter to be lightweight, highly reliable, input/output isolated, flexible and operable in a boost mode. These features can be achieved by using a High-Frequency inverter which involves an isolated DC-DC stage and DC-AC section, which provides AC output. This paper proposes a new three phase topology, based on multi stage converter and PV system in order to use in medium and high power applications. The Perturb and Observe (P&O method is used for maximum power point tracking (MPPT control of PV array. The switching control signals for three-phase inverter are provided by hysteresis control method. Also, the comparison between the proposed topology and traditional structures has been conducted and finally the simulation researches are performed in a closed-loop control system by MATLAB/Simulink software to verify the operation of the proposed structure. The results represent better performance of the introduced system over traditional topologies.

Fast-ion losses induced by ACs and TAEs in the ASDEX Upgrade tokamak

International Nuclear Information System (INIS)

GarcIa-Munoz, M.; Hicks, N.; Classen, I.G.J.; Bilato, R.; Bobkov, V.; Brambilla, M.; Bruedgam, M.; Fahrbach, H.-U.; Igochine, V.; Maraschek, M.; Sassenberg, K.; Van Voornveld, R.; Jaemsae, S.

2010-01-01

The phase-space of convective and diffusive fast-ion losses induced by shear Alfven eigenmodes has been characterized in the ASDEX Upgrade tokamak. Time-resolved energy and pitch-angle measurements of fast-ion losses correlated in frequency and phase with toroidal Alfven eigenmodes (TAEs) and Alfven cascades (ACs) have allowed to identify both loss mechanisms. While single ACs and TAEs eject resonant fast-ions in a convective process, the overlapping of AC and TAE spatial structures leads to a large fast-ion diffusion and loss. The threshold for diffusive fast-ion losses depends on the ion energy (gyroradius). Diffusive fast-ion losses with gyroradius ∼70 mm have been observed with a single TAE for local radial displacements of the magnetic field lines larger than ∼2 mm. Multiple frequency chirping ACs cause an enhancement of the diffusive losses. The ACs and TAEs radial structures have been reconstructed by means of cross-correlation techniques between the fast-ion loss detector and the electron cyclotron emission radiometer.

Investigation of Hybrid Pseudo Bipolar HVDC Performances Supply Power to Passive AC Network

Directory of Open Access Journals (Sweden)

Kuan Li

2014-07-01

Full Text Available The traditional HVDC plays an important role in the development of power grid. But the traditional HVDC cannot supply power either to entirely passive AC network or to weak AC system. In fact, an entirely passive AC network can be effectively powered through VSC-HVDC. However, the cost of investment in VSC-HVDC is amazingly high due to the limitation of power electronics technology. Based on CSC and VSC, this paper proposes a method to build Hybrid HVDC, which makes the power supply to the passive AC network come true and, at the same time, lowers the investment cost. The effect of topology, steady mathematical model, startup characteristic, steady and transient characteristics in Hybrid HVDC system are systematically studied in this paper. The simulation result shows that Hybrid HVDC can supply power to the passive AC network with high stability. This study provides a theoretical basis for the further development of HVDC.

Research on key technology of planning and design for AC/DC hybrid distribution network

Science.gov (United States)

Shen, Yu; Wu, Guilian; Zheng, Huan; Deng, Junpeng; Shi, Pengjia

2018-04-01

With the increasing demand of DC generation and DC load, the development of DC technology, AC and DC distribution network integrating will become an important form of future distribution network. In this paper, the key technology of planning and design for AC/DC hybrid distribution network is proposed, including the selection of AC and DC voltage series, the design of typical grid structure and the comprehensive evaluation method of planning scheme. The research results provide some ideas and directions for the future development of AC/DC hybrid distribution network.

Application of AC servo motor on the in-core neutron flux instrumentation system

International Nuclear Information System (INIS)

Du Xiaoguang; Wang Mingtao

2010-01-01

The application of ac servo motor in the In-Core Neutron Flux Instrumentation System is described. The hardware component of ac servo motor control system is different from the dc motor control system. The effect of two control system on the instrumentation system is compared. The ac servo motor control system can improve the accuracy of the motion control, optimize the speed control and increase the reliability. (authors)

A THREE-PHASE BOOST DC-AC CONVERTER

African Journals Online (AJOL)

dc-ac converter (inverter) based on the dc-dc boost converters. ... Sliding mode controllers are designed to perform a robust control for the ... Computer simulations and spectral analysis demon- ... the conventional three-phase buck inverter,.

Design study of an AC power supply system in JT-60SA

International Nuclear Information System (INIS)

Shimada, Katsuhiro; Baulaigue, Olivier; Cara, Philippe; Coletti, Alberto; Coletti, Roberto; Matsukawa, Makoto; Terakado, Tsunehisa; Yamauchi, Kunihito

2011-01-01

In the initial research phase of JT-60SA, which is the International Thermonuclear Experimental Reactor (ITER) satellite Tokamak with superconducting toroidal and poloidal magnetic field coils, the plasma heating operation of 30 MW-60 s or 20 MW-100 s is planned for 5.5 MA single null divertor plasmas. To achieve this operation, AC power source of the medium voltage of 18 kV and ∼7 GJ has to be provided in total to the poloidal field coil power supplies and additional heating devices such as neutral beam injection (NBI) and electron cyclotron radio frequency (ECRF). In this paper, the proposed AC power supply system in JT-60SA was estimated from the view point of available power, and harmonic currents based on the standard plasma operation scenario during the initial research phase. This AC power supply system consists of the reused JT-60 power supply facilities including motor generators with flywheel, AC breakers, harmonic filters, etc., to make it cost effective. In addition, the conceptual design of the upgraded AC power supply system for the ultimate heating power of 41 MW-100 s in the extended research phase is also described.

AC-Specific Heat and Heat Conductivity Derived from Thermal Effusivity Measurements

DEFF Research Database (Denmark)

Christensen, Tage Emil

It is shown how the 3-omega technique of AC-calorimetry applied to a plane heater with finite dimensions can be improved by including boundary effects.......It is shown how the 3-omega technique of AC-calorimetry applied to a plane heater with finite dimensions can be improved by including boundary effects....

Down-regulation of a novel ABC transporter gene (Pxwhite) is associated with Cry1Ac resistance in the diamondback moth, Plutella xylostella (L.).

Science.gov (United States)

Guo, Zhaojiang; Kang, Shi; Zhu, Xun; Xia, Jixing; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Zhang, Youjun

2015-04-01

Biopesticides or transgenic crops based on Cry toxins from the soil bacterium Bacillus thuringiensis (Bt) effectively control agricultural insect pests. The sustainable use of Bt biopesticides and Bt crops is threatened, however, by the development of Cry resistance in the target pests. The diamondback moth, Plutella xylostella (L.), is the first pest that developed resistance to a Bt biopesticide in the field, and a recent study has shown that the resistance of P. xylostella to Cry1Ac is caused by a mutation in an ATP-binding cassette (ABC) transporter gene (ABCC2). In this study, we report that down-regulation of a novel ABC transporter gene from ABCG subfamily (Pxwhite) is associated with Cry1Ac resistance in P. xylostella. The full-length cDNA sequence of Pxwhite was cloned and analyzed. Spatial-temporal expression detection revealed that Pxwhite was expressed in all tissues and developmental stages, and highest expressed in Malpighian tubule tissue and in egg stage. Sequence variation analysis of Pxwhite indicated the absence of constant non-synonymous mutations between susceptible and resistant strains, whereas midgut transcript analysis showed that Pxwhite was remarkably reduced in all resistant strains and further reduced when larvae of the moderately resistant SZ-R strain were subjected to selection with Cry1Ac toxin. Furthermore, RNA interference (RNAi)-mediated suppression of Pxwhite gene expression significantly reduced larval susceptibility to Cry1Ac toxin, and genetic linkage analysis confirmed that down-regulation of Pxwhite gene is tightly linked to Cry1Ac resistance in P. xylostella. To our knowledge, this is the first report indicating that Pxwhite gene is involved in Cry1Ac resistance in P. xylostella. Copyright © 2015 Elsevier Ltd. All rights reserved.

Project CHECO Southeast Asia Report. OV-1/AC-119 Hunter-Killer Team

Science.gov (United States)

1972-10-10

between Phan Rang, Phu Cat , and Danang in order to provide best coverage of the Vietnamese conflict. -- On 16 February 1970, three AC -ll9Ks and 70...SOUTHEAST ASIA D D DDiv AY/XDOSQA I OV-1/ AC -119 " i IWB I HUNTER-KILLER TEAM 19’.1’ CONTINUING REPORT CLASSIFIED Ey 7AFIDOOC DOWNGRADE TjU SECRET...xamination of C urrent, 0 per’tions I~ I fF!lr T I TII TIIII I OV=1/ AC -119 HUNTER-KILLER TEAMI 1 10 OCTOBER 1972 HQ PACAF Directorate of Operations

Methods to reduce AC losses in HTS coated conductors with magnetic substrates

Energy Technology Data Exchange (ETDEWEB)

Tsukamoto, O. [Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)], E-mail: osami-t@ynu.ac.jp; Sekizawa, S.; Alamgir, A.K.M. [Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan); Miyagi, D. [Okayama University, 1-1, Tsushima-Naka, 1-Chome, Okayama 700-8530 (Japan)

2007-10-01

HTS coated conductors (CCs) have high potentials as low-cost and long length conductors. However, a question remains as to what influence the magnetic property of the substrates has on the AC losses. In this paper, the influence of magnetic property of substrates on the AC losses in HTS CCs is studied. Based on the study methods to reduce the AC transport current losses and magnetization losses in CCs with magnetic substrates are investigated. It is shown that the losses can be reduced to the same level of those in CCs with non-magnetic substrates.

Methods to reduce AC losses in HTS coated conductors with magnetic substrates

International Nuclear Information System (INIS)

Tsukamoto, O.; Sekizawa, S.; Alamgir, A.K.M.; Miyagi, D.

2007-01-01

HTS coated conductors (CCs) have high potentials as low-cost and long length conductors. However, a question remains as to what influence the magnetic property of the substrates has on the AC losses. In this paper, the influence of magnetic property of substrates on the AC losses in HTS CCs is studied. Based on the study methods to reduce the AC transport current losses and magnetization losses in CCs with magnetic substrates are investigated. It is shown that the losses can be reduced to the same level of those in CCs with non-magnetic substrates

Flame spread over inclined electrical wires with AC electric fields

KAUST Repository

Lim, Seung J.

2017-07-21

Flame spread over polyethylene-insulated electrical wires was studied experimentally with applied alternating current (AC) by varying the inclination angle (θ), applied voltage (VAC), and frequency (fAC). For the baseline case with no electric field applied, the flame spread rate and the flame width of downwardly spreading flames (DSFs) decreased from the horizontal case for −20° ≤ θ < 0° and maintained near constant values for −90° ≤ θ < −20°, while the flame spread rate increased appreciably as the inclination angle of upwardly spreading flames (USFs) increased. When an AC electric field was applied, the behavior of flame spread rate in DSFs (USFs) could be classified into two (three) sub-regimes characterized by various functional dependences on VAC, fAC, and θ. In nearly all cases of DSFs, a globular molten polyethylene formed ahead of the spreading flame edge, occasionally dripping onto the ground. In these cases, an effective flame spread rate was defined to represent the burning rate by measuring the mass loss due to dripping. This effective spread rate was independent of AC frequency, while it decreased linearly with voltage and was independent of the inclination angle. In DSFs, when excessively high voltage and frequency were applied, the dripping led to flame extinction during propagation and the extinction frequency correlated well with applied voltage. In USFs, when high voltage and frequency were applied, multiple globular molten PEs formed at several locations, leading to ejections of multiple small flame segments from the main flame, thereby reducing the flame spread rate, which could be attributed to the electrospray phenomenon.

Bees for development: Brazilian survey reveals how to optimize stingless beekeeping.

Directory of Open Access Journals (Sweden)

Rodolfo Jaffé

Full Text Available Stingless bees are an important asset to assure plant biodiversity in many natural ecosystems, and fulfill the growing agricultural demand for pollination. However, across developing countries stingless beekeeping remains an essentially informal activity, technical knowledge is scarce, and management practices lack standardization. Here we profited from the large diversity of stingless beekeepers found in Brazil to assess the impact of particular management practices on productivity and economic revenues from the commercialization of stingless bee products. Our study represents the first large-scale effort aiming at optimizing stingless beekeeping for honey/colony production based on quantitative data. Survey data from 251 beekeepers scattered across 20 Brazilian States revealed the influence of specific management practices and other confounding factors over productivity and income indicators. Specifically, our results highlight the importance of teaching beekeepers how to inspect and feed their colonies, how to multiply them and keep track of genetic lineages, how to harvest and preserve the honey, how to use vinegar traps to control infestation by parasitic flies, and how to add value by labeling honey containers. Furthermore, beekeeping experience and the network of known beekeepers were found to be key factors influencing productivity and income. Our work provides clear guidelines to optimize stingless beekeeping and help transform the activity into a powerful tool for sustainable development.

AC/CRC adjacent lane surfacing : construction report.

Science.gov (United States)

1991-06-01

Asphaltic Concrete (AC) and Portland Cement Concrete (PCC) are common roadway materials used in Oregon. In a recent construction project -- Poverty Flats/Mecham Section -- the Oregon State Highway Division (OSHD) designed, as part of the project, a "...

DIAGNOSTIC FEATURES RESEARCH OF AC ELECTRIC POINT MOTORS

Directory of Open Access Journals (Sweden)

S. YU. Buryak

2014-05-01

Full Text Available Purpose.Considerable responsibility for safety of operation rests on signal telephone and telegraph department of railway. One of the most attackable nodes (both automation systems, and railway in whole is track switches. The aim of this investigation is developing such system for monitoring and diagnostics of track switches, which would fully meet the requirements of modern conditions of high-speed motion and heavy trains and producing diagnostics, collection and systematization of data in an automated way. Methodology. In order to achieve the desired objectives research of a structure and the operating principle description of the switch electric drive, sequence of triggering its main units were carried out. The operating characteristics and settings, operating conditions, the causes of failures in the work, andrequirements for electric drives technology and their service were considered and analyzed. Basic analysis principles of dependence of nature of the changes the current waveform, which flows in the working circuit of AC electric point motor were determined. Technical implementation of the monitoring and diagnosing system the state of AC electric point motors was carried out. Findings. Signals taken from serviceable and defective electric turnouts were researched. Originality. Identified a strong interconnectionbetween the technical condition of the track switchand curve shape that describes the current in the circuit of AC electric point motor during operation which is based on the research processes that have influence on it during operation. Practical value. Shown the principles of the technical approach to the transition from scheduled preventive maintenance to maintenance of real condition for a more objective assessment and thus more rapid response to emerging or failures when they occur gradually, damages and any other shortcomings in the work track switch AC drives.

Professionalism: A Core Competency, but What Does it Mean? A Survey of Surgery Residents.

Science.gov (United States)

Dilday, Joshua C; Miller, Elizabeth A; Schmitt, Kyle; Davis, Brian; Davis, Kurt G

2017-10-27

Professionalism is 1 of the 6 core competencies of the Accreditation Council of Graduate Medical Education. Despite its obvious importance, it is poorly defined in the literature and an understanding of its meaning has not been evaluated on surgical trainees. The American College of Surgeons (ACS) has previously published tenets of surgical professionalism. However, surgery residents may not share similar views on professionalism as those of the ACS. Surgical residents of all levels at 2 surgery residencies located in the same city were interviewed regarding their personal definitions, thoughts, and experiences regarding professionalism during their training. They were then queried regarding 20 points of professionalism as outlined by the ACS tenets of professionalism. The study utilized the surgery residencies at William Beaumont Army Medical Center and Texas Tech University Health Science Center in El Paso, Texas. All general surgery residents at each program were invited to participate in the study. Eighteen residents volunteered to take the survey and be interviewed. The definitions of professionalism centered on clinical competence. Surgery residents conveyed experiences with both professional and unprofessional behavior. Seven of the 20 ACS tenets of professionalism were unanimously agreed upon. There were key differences between resident definitions and those as outlined by the ACS. The least agreed upon ACS tenets of professionalism include professionalism education, public education, and public health. Surgical trainees express personal experiences in both professional and unprofessional behavior. Their definitions of professionalism are not as expansive as those of the ACS and seem to focus on patient and colleague interaction. Due to the lack of congruency, a tailored curriculum for professionalism based upon ACS tenets appears warranted. Published by Elsevier Inc.

Effects of Activated Carbon Surface Property on Structure and Activity of Ru/AC Catalysts

Science.gov (United States)

Xu, S. K.; Li, L. M.; Guo, N. N.

2018-05-01

The activated carbon (AC) was modified by supercritical (SC) methanol, HNO3 oxidation, or HNO3 oxidation plus SC methanol, respectively. Then, the original and the modified AC were used as supports for Ru/AC catalysts prepared via the impregnation method. The results showed that the SC methanol modification decreased the content of surface acidic groups of AC. While HNO3 oxidation displayed the opposite behavior. Furthermore, the dispersion of ruthenium and the activity of catalysts were highly dependent on the content of surface acidic groups, and the SC methanol modified sample exhibited the highest activity for hydrogenation of glucose.

AC distribution system for TFTR pulsed loads

International Nuclear Information System (INIS)

Carroll, R.F.; Ramakrishnan, S.; Lemmon, G.N.; Moo, W.I.

1977-01-01

This paper outlines the AC distribution system associated with the Tokamak Fusion Test Reactor and discusses the significant areas related to design, protection, and equipment selection, particularly where there is a departure from normal utility and industrial applications

Determination of input/output characteristics of full-bridge AC/DC/DC converter for arc welding

OpenAIRE

Stefanov, Goce; Karadzinov, Ljupco; Sarac, Vasilija; Cingoski, Vlatko; Gelev, Saso

2016-01-01

This paper describes the design and practical implementation of AC/DC/DC converter in mode of arc welding. An analysis of the operation of AC/DC/DC converter and its input/output characteristics are determined with computer simulations. The practical part is consisted of AC/DC/DC converter prototype for arc welding with output power of 3 kW and switching frequency of 64 kHz. The operation of AC/DC/DC converter is validated with experimental measurements.

Herbal Medicine AC591 Prevents Oxaliplatin-Induced Peripheral Neuropathy in Animal Model and Cancer Patients

Directory of Open Access Journals (Sweden)

Xiaolan Cheng

2017-06-01

Full Text Available Oxaliplatin is clinically compelling because of severe peripheral neuropathy. The side effect can result in dosage reductions or even cessation of chemotherapy, and no effective treatments are available. AC591 is a standardized extract of Huangqi Guizhi Wuwu decoction, an herbal formula recorded in “Synopsis of the Golden Chamber” for improving limb numbness and pain. In this study, we investigated whether AC591 could protect against oxaliplatin-induced peripheral neuropathy. To clarify it, a rat model of oxaliplatin-induced peripheral neuropathy was established, and neuroprotective effect of AC591 was studied. Our results showed that pretreatment with AC591 reduced oxaliplatin-induced cold hyperalgesia, mechanical allodynia as well as morphological damage of dorsal root ganglion. Microarray analysis indicated the neuroprotective action of AC591 depended on the modulation of multiple molecular targets and pathways involved in the downregulation of inflammation and immune response. Moreover, AC591 enhanced the antitumor activity of oxaliplatin to some extent in Balb/c mice bearing CT-26 carcinoma cells. The efficacy of AC591 is also investigated in 72 colorectal cancer patients. After four cycles of treatment, the percentage of grades 1–2 neurotoxicity in AC591-treated group (n = 36 was 25%, whereas in the control group the incidence was 55.55% (P < 0.01 (n = 36. No significant differences in the tumor response rate between the two groups were found. These evidences suggested that AC591 can prevent oxaliplatin-induced neuropathy without reducing its antitumor activity, and may be a promising adjuvant to alleviate sensory symptoms in clinical practice.

[Accidents of the everyday life (AcVC) in children in Dakar: about 201 cases].

Science.gov (United States)

Mohamed, Azhar Salim; Sagna, Aloïse; Fall, Mbaye; Ndoye, Ndeye Aby; Mbaye, Papa Alassane; Fall, Aimé Lakh; Diaby, Alou; Ndour, Oumar; Ngom, Gabriel

2017-01-01

Accidents of everyday life (AcVC) are common in children and can led to disabling injuries and death. This study aimed to analyze the epidemiological aspects of AcVC and the related injury mechanisms in Dakar. We conducted a descriptive, cross-sectional study conducted from 1 January 2013 to 30 June 2013. All the children victims of domestic accidents, sport and leisure accidents or school accidents were included. We studied some general parameters and some parameters related to each type of AcVC. Two hundred and one children were included, accounting for 27% of emergency consultations. There were 148 boys and 53 girls. Children less than 5 years of age were most affected (37.8%). Football and wrestling game were the main causes of AcVC. AcVC occur mainly at home (58.2%) and in the areas of sport and recreation (31.8%). The fractures predominated in the different types of AcVC: 54.9% of domestic accidents, 68.8% of sport and recreation accidents and 40% of school accidents. From an epidemiological perspective, our results are superimposable to literature. Fractures predominated contrary to literature where bruises were preponderant. Wrestling game is the main cause of these fractures, after football. The acquisition of knowledge about the epidemiological aspects of AcVC and the related injury mechanisms will allow for prevention campaigns in Dakar.

Changes in stimulus and response AC/A ratio with vision therapy in Convergence Insufficiency.

Science.gov (United States)

Singh, Neeraj Kumar; Mani, Revathy; Hussaindeen, Jameel Rizwana

To evaluate the changes in the stimulus and response Accommodative Convergence to Accommodation (AC/A) ratio following vision therapy (VT) in Convergence Insufficiency (CI). Stimulus and response AC/A ratio were measured on twenty five CI participants, pre and post 10 sessions of VT. Stimulus AC/A ratio was measured using the gradient method and response AC/A ratio was calculated using modified Thorington technique with accommodative responses measured using WAM-5500 open-field autorefractor. The gradient stimulus and response AC/A cross-link ratios were compared with thirty age matched controls. Mean age of the CI and control participants were 23.3±5.2 years and 22.7±4.2 years, respectively. The mean stimulus and response AC/A ratio for CI pre therapy was 2.2±0.72 and 6.3±2.0 PD/D that changed to 4.2±0.9 and 8.28±3.31 PD/D respectively post vision therapy and these changes were statistically significant (paired t-test; paccommodation parameters in subjects with convergence insufficiency. This represents the plasticity of the AC/A crosslink ratios that could be achieved with vision therapy in CI. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

AC Own Motion Percentage of Randomly Sampled Cases

Data.gov (United States)

Social Security Administration — Longitudinal report detailing the numbers and percentages of Appeals Council (AC) own motion review actions taken on un-appealed favorable hearing level decisions...

DC response of dust to low frequency AC signals

Science.gov (United States)

McKinlay, Michael; Konopka, Uwe; Thomas, Edward

2017-10-01

Macroscopic changes in the shape and equilibrium position of clouds of charged microparticles suspended in a plasma have been observed in response to low frequency AC signals. In these experiments, dusty plasmas consisting of 2-micron diameter silica microspheres suspended between an anode and cathode in an argon, DC glow discharge plasma are produced in a grounded, 6-way cross vacuum chamber. An AC signal, produced by a function generator and amplified by a bipolar op-amp, is superimposed onto the potential from the cathode. The frequencies of the applied AC signals, ranging from tens to hundreds of kHz, are comparable to the ion-neutral collision frequency; well below the ion/electron plasma frequencies, but also considerably higher than the dust plasma frequency. This presentation will detail the experimental setup, present documentation and categorization of observations of the dust response, and present an initial model of the response. This work is supported by funding from the US Dept. of Energy, Grant Number DE-SC0016330, and by the National Science Foundation, Grant Number PHY-1613087.

Simulation of the AC corona phenomenon with experimental validation

International Nuclear Information System (INIS)

Villa, Andrea; Barbieri, Luca; Marco, Gondola; Malgesini, Roberto; Leon-Garzon, Andres R

2017-01-01

The corona effect, and in particular the Trichel phenomenon, is an important aspect of plasma physics with many technical applications, such as pollution reduction, surface and medical treatments. This phenomenon is also associated with components used in the power industry where it is, in many cases, the source of electro-magnetic disturbance, noise and production of undesired chemically active species. Despite the power industry to date using mainly alternating current (AC) transmission, most of the studies related to the corona effect have been carried out with direct current (DC) sources. Therefore, there is technical interest in validating numerical codes capable of simulating the AC phenomenon. In this work we describe a set of partial differential equations that are comprehensive enough to reproduce the distinctive features of the corona in an AC regime. The model embeds some selectable chemical databases, comprising tens of chemical species and hundreds of reactions, the thermal dynamics of neutral species and photoionization. A large set of parameters—deduced from experiments and numerical estimations—are compared, to assess the effectiveness of the proposed approach. (paper)

SNS AC Power Distribution and Reliability of AC Power Supply

CERN Document Server

Holik, Paul S

2005-01-01

The SNS Project has 45MW of installed power. A design description under the Construction Design and Maintenance (CDM) with regard to regulations (OSHA, NFPA, NEC), reliability issues and maintenance of the AC power distribution system are herewith presented. The SNS Project has 45MW of installed power. The Accelerator Systems are Front End (FE)and LINAC KLYSTRON Building (LK), Central Helium Liquefier (CHL), High Energy Beam Transport (HEBT), Accumulator Ring and Ring to Target Beam Transport (RTBT) Support Buildings have 30MW installed power. FELK has 16MW installed, majority of which is klystron and magnet power supply system. CHL, supporting the super conducting portion of the accelerator has 7MW installed power and the RING Systems (HEBT, RING and RTBT) have also 7MW installed power.*

Negative effect of the 5'-untranslated leader sequence on Ac transposon promoter expression.

Science.gov (United States)

Scortecci, K C; Raina, R; Fedoroff, N V; Van Sluys, M A

1999-08-01

Transposable elements are used in heterologous plant hosts to clone genes by insertional mutagenesis. The Activator (Ac) transposable element has been cloned from maize, and introduced into a variety of plants. However, differences in regulation and transposition frequency have been observed between different host plants. The cause of this variability is still unknown. To better understand the activity of the Ac element, we analyzed the Ac promoter region and its 5'-untranslated leader sequence (5' UTL). Transient assays in tobacco NT1 suspension cells showed that the Ac promoter is a weak promoter and its activity was localized by deletion analyses. The data presented here indicate that the core of the Ac promoter is contained within 153 bp fragment upstream to transcription start sites. An important inhibitory effect (80%) due to the presence of the 5' UTL was found on the expression of LUC reporter gene. Here we demonstrate that the presence of the 5' UTL in the constructs reduces the expression driven by either strong or weak promoters.

Measurement of AC losses in superconducting tapes by reproduction of thermometric dynamic response

Energy Technology Data Exchange (ETDEWEB)

Ligneris, Benoit des; Aubin, Marcel; Cave, Julian

2003-04-15

We have developed a dynamic response thermometric method for the measurement of AC losses in high T{sub c} superconductors. This method is based on the comparison of a temperature response caused by a known dissipation in the sample with that produced by the AC losses. By passing a DC current and measuring the DC voltage and corresponding temperature response the sample can be used as its own power dissipation reference. The advantages of this method are the short measurement duration time and the possibility to vary many experimental conditions: for example, AC and DC transport currents and AC, DC and rotating applied magnetic fields. In this article we present the basic method using variable short pulses of constant DC current for calibration and similarly of constant amplitude AC current to create the losses. The losses are obtained by numerical modelling and comparison of the thermometric dynamic response in the two above conditions. Finally, we present some experimental results for a Bi2223 superconducting tape at 50 Hz and 77 K.

Transmission Technologies and Operational Characteristic Analysis of Hybrid UHV AC/DC Power Grids in China

Science.gov (United States)

Tian, Zhang; Yanfeng, Gong

2017-05-01

In order to solve the contradiction between demand and distribution range of primary energy resource, Ultra High Voltage (UHV) power grids should be developed rapidly to meet development of energy bases and accessing of large-scale renewable energy. This paper reviewed the latest research processes of AC/DC transmission technologies, summarized the characteristics of AC/DC power grids, concluded that China’s power grids certainly enter a new period of large -scale hybrid UHV AC/DC power grids and characteristics of “strong DC and weak AC” becomes increasingly pro minent; possible problems in operation of AC/DC power grids was discussed, and interaction or effect between AC/DC power grids was made an intensive study of; according to above problems in operation of power grids, preliminary scheme is summarized as fo llows: strengthening backbone structures, enhancing AC/DC transmission technologies, promoting protection measures of clean energ y accessing grids, and taking actions to solve stability problems of voltage and frequency etc. It’s valuable for making hybrid UHV AC/DC power grids adapt to operating mode of large power grids, thus guaranteeing security and stability of power system.

Twelve Years of the HST Advanced Camera for Surveys : Calibration Update

Science.gov (United States)

Grogin, Norman A.

2014-06-01

The Advanced Camera for Surveys (ACS) has been a workhorse HST imager for over twelve years, subsequent to its Servicing Mission 3B installation. The once defunct ACS Wide Field Channel (WFC) has now been operating longer since its Servicing Mission 4 repair than it had originally operated prior to its 2007 failure. Despite the accumulating radiation damage to the WFC CCDs during their long stay in low Earth orbit, ACS continues to be heavily exploited by the HST community as both a prime and a parallel detector. Conspicuous examples include the recently completed HST Multi-cycle Treasury programs, and the ongoing HST Frontier Fields (HFF) program.We review recent developments in ACS calibration that enable the continued high performance of this instrument, with particular attention the to the Wide Field Channel. Highlights include: 1) the refinement of the WFC geometric distortion solution and its time dependency; 2) the efficacy of both pixel-based and catalog-based corrections for the worsening WFC charge-transfer efficiency (CTE); 3) the extension of pixel-based CTE correction to the WFC 2K subarray mode; and 4) a novel "self-calibration" technique appropriate for large-number stacks of deep WFC exposures (such as the HFF targets) that provides superior reductions compared to the standard CALACS reduction pipeline.

AC loss in superconducting tapes and cables

NARCIS (Netherlands)

Oomen, M.P.

2000-01-01

The present study discusses the AC loss in high-temperature superconductors. Superconducting materials with a relatively high critical temperature were discovered in 1986. They are presently developed for use in large-scale power-engineering devices such as power-transmission cables, transformers

AC-Conductivity measurements on γ-aluminium oxynitride

NARCIS (Netherlands)

Willems, H.X.; Hal, van P.F.; Metselaar, R.; With, de G.

1995-01-01

AC-conductivity measurements were performed on aluminium oxynitrides (Alons) because of their interesting defect structure. Although it became apparent that these Alons are not stable in the temperature range used, the electrical properties of the materials could be measured with impedance

Risk prediction of ventricular arrhythmias and myocardial function in Lamin A/C mutation positive subjects

DEFF Research Database (Denmark)

Hasselberg, Nina E; Edvardsen, Thor; Petri, Helle

2014-01-01

Mutations in the Lamin A/C gene may cause atrioventricular block, supraventricular arrhythmias, ventricular arrhythmias (VA), and dilated cardiomyopathy. We aimed to explore the predictors and the mechanisms of VA in Lamin A/C mutation-positive subjects.METHODS AND RESULTS: We included 41 Lamin A/C...

Numerical evaluation of guidance force decay of HTS bulk exposed to AC magnetic field over a NdFeB guideway

Energy Technology Data Exchange (ETDEWEB)

Zhang Longcai [P.O. Box 152, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)], E-mail: zhlcai2000@163.com; Wang Jiasu; Wang Suyu; Zheng Jun; He Qingyong [P.O. Box 152, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

2007-12-01

The guidance force of the YBCO bulk over a NdFeB guideway used in the high-temperature superconducting maglev vehicle system was decayed by the application of the AC external magnetic field. In our previous work, we explained that the decay was due to the temperature rise of the HTS bulk caused by AC losses. In this paper, we adopted an analytic model to evaluate the decay of the critical current density of the bulk. And based on the analytic results and the Bean critical-state model, we calculated the guidance force as a function of times. Compared with the experimental results, the calculation results have almost the same trend and can qualitatively reveal the characteristics of guidance force of HTS bulk in this situation. Therefore, the guidance force decay of HTS bulk in the maglev vehicle system can be evaluated simply by this numerical method.

Magneto-optical measurements on high-temperature superconductors influenced by AC-fields

International Nuclear Information System (INIS)

Che'Rose, Simon

2007-01-01

In this work magneto-optical measurements on YBa 2 Cu 3 O 7-x and MgB 2 thin films were done. For YBCO the influence of AC-pulses on the flux and current density of a thin film with transport current was investigated. For MgB 2 the influence of AC-fields on the homogenous and dendritic flux penetration was researched. (orig.)

Protective effect of Ac-SDKP on alveolar epithelial cells through inhibition of EMT via TGF-β1/ROCK1 pathway in silicosis in rat

International Nuclear Information System (INIS)

Deng, Haijing; Xu, Hong; Zhang, Xianghong; Sun, Yue; Wang, Ruimin; Brann, Darrell; Yang, Fang

2016-01-01

The epithelial–mesenchymal transition (EMT) is a critical stage during the development of silicosis fibrosis. In the current study, we hypothesized that the anti-fibrotic tetrapeptide, N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) may exert its anti-fibrotic effects via activation of the TGF-β1/ROCK1 pathway, leading to inhibition of EMT. To address this hypothesis, we first examined the effect of Ac-SDKP upon EMT using an in vivo rat silicosis model, as well as in an in vitro model of TGF-β1-induced EMT. Confocal laser scanning microscopy was used to examine colocalization of surfactant protein A (SP-A), fibroblast specific protein-1 (FSP-1) and α-smooth muscle actin (α-SMA) in vivo. Western blot analysis was used to examine for changes in the protein levels of E-cadherin (E-cad) and SP-A (epithelial cell markers), vimentin (mesenchymal cell marker), α-SMA (active myofibroblast marker), and collagen I and III in both in vivo and in vitro experiments. Secondly, we utilized Western blot analysis and confocal laser scanning microscopy to examine the protein expression of TGF-β1 and ROCK1 in in vivo and in vitro studies. The results revealed that Ac-SDKP treatment prevented increases in the expression of mesenchymal markers as well as TGF-β1, ROCK1, collagen I and III. Furthermore, Ac-SDKP treatment prevented decreases in the expression of epithelial cell markers in both in vivo and in vitro experiments. Based on the results, we conclude that Ac-SDKP inhibits the transition of epithelial cell-myofibroblast in silicosis via activation of the TGF-β1/ROCK1 signaling pathway, which may serve as a novel mechanism by which it exerts its anti-fibrosis properties. - Highlights: • EMT is a critical stage during the development of silicosis fibrosis. • Ac-SDKP inhibits the EMT process in silicosis both in vivo and in vitro. • Ac-SDKP inhibits the EMT process in silicosis via TGF-β1/ROCK1 pathway.

Protective effect of Ac-SDKP on alveolar epithelial cells through inhibition of EMT via TGF-β1/ROCK1 pathway in silicosis in rat

Energy Technology Data Exchange (ETDEWEB)

Deng, Haijing [School of Basic Medical Sciences, North China University of Science and Technology, Tangshan (China); Xu, Hong [Medical Research Center, International Science and Technology Cooperation Base of Geriatric Medicine, North China University of Science and Technology, Tangshan (China); Zhang, Xianghong [Pathology Department, Hebei Medical University, Shi Jiazhuang (China); Sun, Yue; Wang, Ruimin [Medical Research Center, International Science and Technology Cooperation Base of Geriatric Medicine, North China University of Science and Technology, Tangshan (China); Brann, Darrell [Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912 (United States); Yang, Fang, E-mail: fangyang1978@163.com [Medical Research Center, International Science and Technology Cooperation Base of Geriatric Medicine, North China University of Science and Technology, Tangshan (China)

2016-03-01

The epithelial–mesenchymal transition (EMT) is a critical stage during the development of silicosis fibrosis. In the current study, we hypothesized that the anti-fibrotic tetrapeptide, N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) may exert its anti-fibrotic effects via activation of the TGF-β1/ROCK1 pathway, leading to inhibition of EMT. To address this hypothesis, we first examined the effect of Ac-SDKP upon EMT using an in vivo rat silicosis model, as well as in an in vitro model of TGF-β1-induced EMT. Confocal laser scanning microscopy was used to examine colocalization of surfactant protein A (SP-A), fibroblast specific protein-1 (FSP-1) and α-smooth muscle actin (α-SMA) in vivo. Western blot analysis was used to examine for changes in the protein levels of E-cadherin (E-cad) and SP-A (epithelial cell markers), vimentin (mesenchymal cell marker), α-SMA (active myofibroblast marker), and collagen I and III in both in vivo and in vitro experiments. Secondly, we utilized Western blot analysis and confocal laser scanning microscopy to examine the protein expression of TGF-β1 and ROCK1 in in vivo and in vitro studies. The results revealed that Ac-SDKP treatment prevented increases in the expression of mesenchymal markers as well as TGF-β1, ROCK1, collagen I and III. Furthermore, Ac-SDKP treatment prevented decreases in the expression of epithelial cell markers in both in vivo and in vitro experiments. Based on the results, we conclude that Ac-SDKP inhibits the transition of epithelial cell-myofibroblast in silicosis via activation of the TGF-β1/ROCK1 signaling pathway, which may serve as a novel mechanism by which it exerts its anti-fibrosis properties. - Highlights: • EMT is a critical stage during the development of silicosis fibrosis. • Ac-SDKP inhibits the EMT process in silicosis both in vivo and in vitro. • Ac-SDKP inhibits the EMT process in silicosis via TGF-β1/ROCK1 pathway.

An improved power control strategy for hybrid AC-DC microgrids

DEFF Research Database (Denmark)

Baharizadeh, Mehdi; Karshenas, Hamid Reza; Guerrero, Josep M.

2018-01-01

This paper presents a new droop-based control strategy for hybrid microgrids (HMG) with improved power sharing. When ac microgrids (AC-MG) and dc microgrids (DC-MG) are present in a distribution grid, there is an opportunity to interconnect them via an interlinking converter (IC) and form a HMG......, the possibility of participation of IC in AC-MG reactive power adds some complexity to a HMG control system. In this paper, a new decentralized control strategy is presented for a HMG which relies on regulating the voltage magnitude of a common bus in each microgrid. In this regard, new droop characteristics...... for sources across both microgrids as well as IC are proposed. The proposed droop characteristics result in better active/reactive power sharing across both microgrids and at the same time results in better voltage regulation. The derivation of new droop characteristics is thoroughly discussed in this paper...

Structural, ac conductivity and dielectric properties of 3-formyl chromone

Science.gov (United States)

Ali, H. A. M.

2017-07-01

The structure for the powder of 3-formyl chromone was examined by X-ray diffraction technique in the 2θ° range ( 4° - 60° . The configuration of Al/3-formyl chromone/Al samples was designed. The electrical and dielectric properties were studied as a function of frequency (42- 5 × 106 Hz) and temperature (298-408K). The ac conductivity data of bulk of 3-formyl chromone varies as a power law with the frequency at different temperatures. The predominant mechanism for ac conduction was deduced. The ac conductivity shows a thermally activated process at different frequencies. The dielectric constant and dielectric loss were determined using the capacitance and dissipation factor measurements at different temperatures. The dielectric loss shows a peak of relaxation time that shifted to higher frequency with an increase in the temperature. The activation energy of the relaxation process was estimated.

Transgenic cotton coexpressing Vip3A and Cry1Ac has a broad insecticidal spectrum against lepidopteran pests.

Science.gov (United States)

Chen, Wen-Bo; Lu, Guo-Qing; Cheng, Hong-Mei; Liu, Chen-Xi; Xiao, Yu-Tao; Xu, Chao; Shen, Zhi-Cheng; Wu, Kong-Ming

2017-10-01

Although farmers in China have grown transgenic Bt-Cry1Ac cotton to resist the major pest Helicoverpa armigera since 1997 with great success, many secondary lepidopteran pests that are tolerant to Cry1Ac are now reported to cause considerable economic damage. Vip3AcAa, a chimeric protein with the N-terminal part of Vip3Ac and the C-terminal part of Vip3Aa, has a broad insecticidal spectrum against lepidopteran pests and has no cross resistance to Cry1Ac. In the present study, we tested insecticidal activities of Vip3AcAa against Spodoptera litura, Spodoptera exigua, and Agrotis ipsilon, which are relatively tolerant to Cry1Ac proteins. The bioassay results showed that insecticidal activities of Vip3AcAa against these three pests are superior to Cry1Ac, and after an activation pretreatment, Vip3AcAa retained insecticidal activity against S. litura, S. exigua and A. ipsilon that was similar to the unprocessed protein. The putative receptor for this chimeric protein in the brush border membrane vesicle (BBMV) in the three pests was also identified using biotinylated Vip3AcAa toxin. To broaden Bt cotton activity against a wider spectrum of pests, we introduced the vip3AcAa and cry1Ac genes into cotton. Larval mortality rates for S. litura, A. ipsilon and S. exigua that had fed on this new cotton increased significantly compared with larvae fed on non-Bt cotton and Bt-Cry1Ac cotton in a laboratory experiment. These results suggested that the Vip3AcAa protein is an excellent option for a "pyramid" strategy for integrated pest management in China. Copyright © 2017 Elsevier Inc. All rights reserved.

AC conductivity and dielectric properties of bulk tungsten trioxide (WO3)

Science.gov (United States)

El-Nahass, M. M.; Ali, H. A. M.; Saadeldin, M.; Zaghllol, M.

2012-11-01

AC conductivity and dielectric properties of tungsten trioxide (WO3) in a pellet form were studied in the frequency range from 42 Hz to 5 MHz with a variation of temperature in the range from 303 K to 463 K. AC conductivity, σac(ω) was found to be a function of ωs where ω is the angular frequency and s is the frequency exponent. The values of s were found to be less than unity and decrease with increasing temperature, which supports the correlated barrier hopping mechanism (CBH) as the dominant mechanism for the conduction in WO3. The dielectric constant (ε‧) and dielectric loss (ε″) were measured. The Cole-Cole diagram determined complex impedance for different temperatures.

Reliability of the emergency AC power system at nuclear power plants

International Nuclear Information System (INIS)

Battle, R.E.; Campbell, D.J.; Baranowsky, P.W.

1983-01-01

The reliability of the emergency ac power systems typical of most nuclear power plants was estimated, and the cost and increase in reliability for several improvements were estimated. Fault trees were constructed based on a detailed design review of the emergency ac power systems of 18 nuclear plants. The failure probabilities used in the fault trees were calculated from extensive historical data collected from Licensee Event Reports (LERs) and from operating experience information obtained from nuclear plant licensees. No one or two improvements can be made at all plants to significantly increase the industry-average emergency ac power system reliability; rather the most beneficial improvements are varied and plant specific. Improvements in reliability and the associated costs are estimated using plant specific designs and failure probabilities

Effect of ac electric fields on counterflow diffusion flame of methane

KAUST Repository

Chul Choi, Byung

2012-08-01

The effect of electric fields on the response of diffusion flames in a counterflow has been investigated experimentally by varying the AC voltage and frequency. The result showed that the flame was stationary with high AC frequency above the threshold frequency, and it increased with the applied voltage and then leveled off at 35 Hz. Below the threshold frequency, however, the flame oscillated with a frequency that was synchronized with the applied AC frequency. This oscillation can be attributed to the ionic wind effect due to the generation of bulk flow, which arises from the momentum transfer by molecular collisions between neutral molecules and ions, where the ions in the reaction zone were accelerated by the Lorentz force. © 2012 The Korean Society of Mechanical Engineers.

Effect of ac electric fields on counterflow diffusion flame of methane

KAUST Repository

Chul Choi, Byung; Kuk Kim, Hyung; Chung, Suk-Ho

2012-01-01

The effect of electric fields on the response of diffusion flames in a counterflow has been investigated experimentally by varying the AC voltage and frequency. The result showed that the flame was stationary with high AC frequency above the threshold frequency, and it increased with the applied voltage and then leveled off at 35 Hz. Below the threshold frequency, however, the flame oscillated with a frequency that was synchronized with the applied AC frequency. This oscillation can be attributed to the ionic wind effect due to the generation of bulk flow, which arises from the momentum transfer by molecular collisions between neutral molecules and ions, where the ions in the reaction zone were accelerated by the Lorentz force. © 2012 The Korean Society of Mechanical Engineers.

Autonomous Operation of a Hybrid AC/DC Microgrid with Multiple Interlinking Converters

DEFF Research Database (Denmark)

Peyghami, Saeed; Mokhtari, Hossein; Blaabjerg, Frede

2018-01-01

Applying conventional dc-voltage based droop approaches for hybrid ac/dc microgrids interconnected by a single interlinking converter (IC) can properly manage the power flow among ac and dc subgrids. However, due to the effect of line resistances, these approaches may create a circulating power a...

Control of a resonant d.c.-link converter for a.c. motor drives

Directory of Open Access Journals (Sweden)

Astrid Petterteig

1992-10-01

Full Text Available This paper presents the control of the resonant d.c.-link converter for a.c. motor drives. This is a low loss converter with higher efficiency than a conventional PWM converter, but it requires complex control. It needs a special control of the resonant d.c.-link voltage in addition to the discrete control of the a.c. side currents. Simulations show how the control of the a.c. currents, the modulation principle, influences the overall performance of the converter.

A method for decreasing transport ac losses in multifilamentary and multistrip superconductors

Energy Technology Data Exchange (ETDEWEB)

Glowacki, B A [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Majoros, M [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom)

2000-07-01

A new method is proposed for decreasing transport ac losses in multifilamentary superconductors by the decoupling of the filaments using a magnetic material in the form of thin layers surrounding the individual filaments. For a superconductor with an elliptical cross section, the magnetic material surrounding the filaments affects the local magnetic field distribution that both reduces the critical current of the filaments and induces the transport ac losses in the magnetic material. Even by taking into account any detrimental influences of the presence of the magnetic material around the filaments, the analysis of the experimental data supported by computer modelling confirmed that for a Bi2223 tape with 100 filaments individually covered by magnetic material, such as iron powder, the transport ac losses should be 65 times lower than for the same multifilamentary conductor without the magnetic coating on the filaments. With an increasing number of filaments, the ac loss decrease would be even larger. (author)

Experimental infection with Escherichia coli 0149 : F4ac in weaned piglets

DEFF Research Database (Denmark)

Jensen, Gerda M.; Frydendahl, Kai; Svendsen, Ove

2006-01-01

adhesion test made after slaughter of piglets. However, in an experimental infection study with the purpose to obtain diarrhoeic piglets, it would be an advantage to test for susceptibility prior to experimentation. The Mucin 4 gene on porcine chromosome 13 has been proposed as a candidate gene...... for the production of the specific ETEC F4ab/ac receptor, and a DNA marker-based test has been developed to allow genotyping for ETEC F4ab/ac resistance/susceptibility [Jorgensen, C.B., Cirera, S., Archibald, A.L., Anderson, L., Fredholm, M., Edfors-Lilja, I., 2004. Porcine polymorphisms and methods for detecting...... them. International application published under the patent cooperation treaty (PCT). PCT/DK2003/000807 or WO2004/048606-A2]. The aim of this study was to test an experimental model for ETEC O149:F4ac-induced diarrhoea in piglets, selected for susceptibility towards ETEC O149:F4ac adhesion prior...

DC Vs AC - War Of Currents For Future Power Systems A HVDC Technology Overview

Directory of Open Access Journals (Sweden)

Anil K. Rai

2015-08-01

Full Text Available DC vs AC discussion began in 1880s with development of first commercial power transmission in Wall Street New York. Later when AC technology came into notice by efforts of inventor and researcher Sir Nicola Tesla soon the advantages of AC transmission and AC devices overtook the DC technology. It was hoped that DC technology had lost battle of currents. Today with researches going on FACTS devices and bulk power transmission HVDC has again gained a reputation in power sector. Solution of this centuries old debate is to develop HVDC systems that assists HVAC systems for better performance stability and control

File list: His.PSC.10.H3K122ac.AllCell [Chip-atlas[Archive

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Full Text Available His.PSC.10.H3K122ac.AllCell mm9 Histone H3K122ac Pluripotent stem cell ERX631826,ER...X631814 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.10.H3K122ac.AllCell.bed ...

File list: His.PSC.05.H3K122ac.AllCell [Chip-atlas[Archive

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Full Text Available His.PSC.05.H3K122ac.AllCell mm9 Histone H3K122ac Pluripotent stem cell ERX631826,ER...X631814 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.05.H3K122ac.AllCell.bed ...

File list: His.PSC.50.H3K122ac.AllCell [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.PSC.50.H3K122ac.AllCell mm9 Histone H3K122ac Pluripotent stem cell ERX631826,ER...X631814 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.50.H3K122ac.AllCell.bed ...

New three-phase ac-ac converter incorporating three-phase boost integrated ZVT bridge and single-phase HF link

International Nuclear Information System (INIS)

Abdelhamid, Tamer H.; Sabzali, Ahmad J.

2008-01-01

This paper presents a new zero voltage transition (ZVT), power factor corrected three phase ac-ac converter with single phase high frequency (HF) link. It is a two stage converter; the first stage is a boost integrated bridge converter (combination of a 3 ph boost converter and a bridge converter) operated at fixed frequency and that operates in two modes at ZVT for all switches and establishes a 1 ph square wave HF link. The second stage is a bi-directional pulse width modulation (PWM) 3 ph bridge that converts the 1 ph HF link to a 3 ph voltage using a novel switching strategy. The converter modes of operation and key equations are outlined. Simulation of the overall system is conducted using Simulink. The switching strategy and its corresponding control circuit are clearly described. Experimental verification of the simulation is conducted for a prototype of 100 V, 500 W at 10 kHz link frequency

Thrust distribution for attitude control in a variable thrust propulsion system with four ACS nozzles

Science.gov (United States)

Lim, Yeerang; Lee, Wonsuk; Bang, Hyochoong; Lee, Hosung

2017-04-01

A thrust distribution approach is proposed in this paper for a variable thrust solid propulsion system with an attitude control system (ACS) that uses a reduced number of nozzles for a three-axis attitude maneuver. Although a conventional variable thrust solid propulsion system needs six ACS nozzles, this paper proposes a thrust system with four ACS nozzles to reduce the complexity and mass of the system. The performance of the new system was analyzed with numerical simulations, and the results show that the performance of the system with four ACS nozzles was similar to the original system while the mass of the whole system was simultaneously reduced. Moreover, a feasibility analysis was performed to determine whether a thrust system with three ACS nozzles is possible.

Cost effective second generation AC-modules: Development and testing aspects

International Nuclear Information System (INIS)

Islam, Saiful; Woyte, Achim; Belmans, Ronnie; Heskes, Peter; Rooij, P.M.; Hogedoorn, Ron

2006-01-01

In the framework of the European research project PV2GO, a new AC-module inverter was developed, taking into account all relevant aspects from a European market's point of view (standards, market, application, and research and development goals). The project goal was to achieve the overall system costs of 3 Euro per Wp for a modular plug-and-play photovoltaic system. For the photovoltaic-module, a standard 130-Wp Eurosolare module was chosen. The research and development (R and D) goal was to develop an advanced DC-control system consisting of a state-of-the-art programmable digital device and an Application Specific Integrated Circuit (ASIC) for the AC-control of the inverter. According to the topology concept, thermal and magnetic designs were optimized with regard to production technology and packaging for large-scale production. The new AC-modules were tested in a number of field-test sites in various parts of Europe and their reliability was assessed through Highly Accelerated Stress Tests. Efficiency and power quality have been tested in the laboratory. Further in the PV2GO project an optimization study of the manufacturing process of the new generation of AC-modules for high volume output was done. Another task was the pre-certification procedure to assure compliance with the European guidelines and standards

Meso Mechanical Analysis of AC Mixture Response

NARCIS (Netherlands)

Woldekidan, M.F.; Huurman, M.; Vaccari, E.; Poot, M.

2012-01-01

Ongoing research into performance modeling of Asphalt Concrete (AC) mixtures using meso mechanics approaches is being undertaken at Delft University of Technology (TUD). The approach has already been successfully employed for evaluating the long term performance of porous asphalt concrete. The work

Susceptibility of The Asian Corn Borer, Ostrinia furnacalis, to Bacillus thuringiensis Toxin CRY1AC

Directory of Open Access Journals (Sweden)

Aye Kyawt Kyawt Ei

2008-07-01

Full Text Available The larval susceptibility of the Asian corn borer, Ostrinia furnacalis (Guenee (Lepidoptera: Crambidae, to a Bacillus thuringiensis protein (Cry1Ac was evaluated using insect feeding bioassays. The founding population of O. furnacalis was originally collected from the experimental station of UGM at Kalitirto and had been reared in the laboratory for three generations using an artificial diet “InsectaLf”. The tested instars were exposed on diets treated with a series of concentrations of Cry1Ac for one week. The LC50 values on the seventh day after treatment for 1st, 2nd, 3rd and 4th instars were 7.79, 21.12, 113.66, and 123.17 ppm, respectively, showing that the higher the instars the lesser the susceptibility to Cry1Ac. When the neonates were exposed to sublethal concentrations of Cry1Ac (0.0583, 0.116, and 0.5830 ppm, growth and development of the surviving larvae were inhibited. The fecundity and viability of females produced from treated larvae decreased with increasing the concentrations. These findings indicate that Cry1Ac is toxic to larva of O. furnacalis and has chronic effects to larvae surviving from Cry1Ac ingestion.   Kepekaan larva penggerek batang jagung Asia, Ostrinia furnacalis (Guenee (Lepidoptera: Crambidae, terhadap protein Bacillus thuringiensis Cry1Ac diuji dengan metode celup pakan. Larva berasal dari pertanaman jagung di KP-4, UGM di Kalitirto dan telah dikembangbiakkan di laboratorium menggunakan pakan buatan (InsectaLF selama tiga generasi sebelum digunakan untuk pengujian. Larva O. furnacalis yang diuji dipaparkan pada pakan buatan yang telah dicelupkan pada seri konsentrasi Cry1Ac. Nilai LC50 pada hari ketujuh setelah perlakukan untuk instar 1, 2, 3, dan 4 berturut-turut adalah 0,79; 21,12; 113,66; dan 123,17 ppm. Hal ini menunjukkan bahwa instar yang semakin tinggi tingkat kepekaannya terhadap Cry1Ac semakin menurun. Larva yang baru menetas dan diberi pakan yang telah dicelupkan pada konsentrasi sublethal Cry1Ac

AC Loss Analysis of MgB2-Based Fully Superconducting Machines

Science.gov (United States)

Feddersen, M.; Haran, K. S.; Berg, F.

2017-12-01

Superconducting electric machines have shown potential for significant increase in power density, making them attractive for size and weight sensitive applications such as offshore wind generation, marine propulsion, and hybrid-electric aircraft propulsion. Superconductors exhibit no loss under dc conditions, though ac current and field produce considerable losses due to hysteresis, eddy currents, and coupling mechanisms. For this reason, many present machines are designed to be partially superconducting, meaning that the dc field components are superconducting while the ac armature coils are conventional conductors. Fully superconducting designs can provide increases in power density with significantly higher armature current; however, a good estimate of ac losses is required to determine the feasibility under the machines intended operating conditions. This paper aims to characterize the expected losses in a fully superconducting machine targeted towards aircraft, based on an actively-shielded, partially superconducting machine from prior work. Various factors are examined such as magnet strength, operating frequency, and machine load to produce a model for the loss in the superconducting components of the machine. This model is then used to optimize the design of the machine for minimal ac loss while maximizing power density. Important observations from the study are discussed.

Electrodeformation of multi-bilayer spherical concentric membranes by AC electric fields

Science.gov (United States)

Lira-Escobedo, J.; Arauz-Lara, J.; Aranda-Espinoza, H.; Adlerz, K.; Viveros-Mendez, P. X.; Aranda-Espinoza, S.

2017-09-01

It is now well established that external stresses alter the behaviour of cells, where such alterations can be as profound as changes in gene expression. A type of stresses of particular interest are those due to alternating-current (AC) electric fields. The effect of AC fields on cells is still not well understood, in particular it is not clear how these fields affect the cell nucleus and other organelles. Here, we propose that one possible mechanism is through the deformation of the membranes. In order to investigate the effect of AC fields on the morphological changes of the cell organelles, we modelled the cell as two concentric bilayer membranes. This model allows us to obtain the deformations induced by the AC field by balancing the elastic energy and the work done by the Maxwell stresses. Morphological phase diagrams are obtained as a function of the frequency and the electrical properties of the media and membranes. We demonstrate that the organelle shapes can be changed without modifying the shape of the external cell membrane and that the organelle deformation transitions can be used to measure, for example, the conductivity of the nucleus.

Acquisition of Cry1Ac protein by non-target arthropods in Bt soybean fields.

Directory of Open Access Journals (Sweden)

Huilin Yu

Full Text Available Soybean tissue and arthropods were collected in Bt soybean fields in China at different times during the growing season to investigate the exposure of arthropods to the plant-produced Cry1Ac toxin and the transmission of the toxin within the food web. Samples from 52 arthropod species/taxa belonging to 42 families in 10 orders were analysed for their Cry1Ac content using enzyme-linked immunosorbent assay (ELISA. Among the 22 species/taxa for which three samples were analysed, toxin concentration was highest in the grasshopper Atractomorpha sinensis and represented about 50% of the concentration in soybean leaves. Other species/taxa did not contain detectable toxin or contained a concentration that was between 1 and 10% of that detected in leaves. These Cry1Ac-positive arthropods included a number of mesophyll-feeding Hemiptera, a cicadellid, a curculionid beetle and, among the predators, a thomisid spider and an unidentified predatory bug belonging to the Anthocoridae. Within an arthropod species/taxon, the Cry1Ac content sometimes varied between life stages (nymphs/larvae vs. adults and sampling dates (before, during, and after flowering. Our study is the first to provide information on Cry1Ac-expression levels in soybean plants and Cry1Ac concentrations in non-target arthropods in Chinese soybean fields. The data will be useful for assessing the risk of non-target arthropod exposure to Cry1Ac in soybean.

Acquisition of Cry1Ac Protein by Non-Target Arthropods in Bt Soybean Fields

Science.gov (United States)

Yu, Huilin; Romeis, Jörg; Li, Yunhe; Li, Xiangju; Wu, Kongming

2014-01-01

Soybean tissue and arthropods were collected in Bt soybean fields in China at different times during the growing season to investigate the exposure of arthropods to the plant-produced Cry1Ac toxin and the transmission of the toxin within the food web. Samples from 52 arthropod species/taxa belonging to 42 families in 10 orders were analysed for their Cry1Ac content using enzyme-linked immunosorbent assay (ELISA). Among the 22 species/taxa for which three samples were analysed, toxin concentration was highest in the grasshopper Atractomorpha sinensis and represented about 50% of the concentration in soybean leaves. Other species/taxa did not contain detectable toxin or contained a concentration that was between 1 and 10% of that detected in leaves. These Cry1Ac-positive arthropods included a number of mesophyll-feeding Hemiptera, a cicadellid, a curculionid beetle and, among the predators, a thomisid spider and an unidentified predatory bug belonging to the Anthocoridae. Within an arthropod species/taxon, the Cry1Ac content sometimes varied between life stages (nymphs/larvae vs. adults) and sampling dates (before, during, and after flowering). Our study is the first to provide information on Cry1Ac-expression levels in soybean plants and Cry1Ac concentrations in non-target arthropods in Chinese soybean fields. The data will be useful for assessing the risk of non-target arthropod exposure to Cry1Ac in soybean. PMID:25110881

The stability of DOTA-chelated radiopharmaceuticals within 225Ac decay pathway studied with density functional theory.

Science.gov (United States)

Karolak, Aleksandra; Khabibullin, Artem; Budzevich, Mikalai; Martinez, M.; Doliganski, Michael; McLaughlin, Mark; Woods, Lilia; Morse, David

Ligand structures encapsulating metal ions play a central role as contrast agents in Magnetic Resonance Imaging (MRI) or as agents delivering toxic cargo directly to tumor cells in targeted cancer therapy. The structural stability and interaction with solutions of such complexes are the key elements in understanding the foundation of delivery process. We present a comparative study for the 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelated to radioactive isotopes of 225Ac, 221Fr, 217At, 213Bi and a control 68Gd. Using density functional theory methods we investigate the structural stability of complexes for cancer therapy including binding energies, charge transfer, electron densities. The van der Waals interactions are included in the simulations to take into account weak dispersion forces present in such structures. Our results reveal that Ac-DOTA, Bi-DOTA and Gd-DOTA are the most stable complexes in the group. We also show that the water environment is a key ingredient for the structural coordination of the DOTA structures. Support from the US Department of Energy under Grant No. DE-FG02-06ER46297 is acknowledged.

VizieR Online Data Catalog: LMC NIR Synoptic Survey. II. Wesenheit relations (Bhardwaj+, 2016)

Science.gov (United States)

Bhardwaj, A.; Kanbur, S. M.; Macri, L. M.; Singh, H. P.; Ngeow, C.-C.; Wagner-Kaiser, R.; Sarajedini, A.

2018-03-01

We make use of NIR mean magnitudes for 775 fundamental-mode and 474 first-overtone Cepheids in the LMC from Macri et al. 2015, J/AJ/149/117 (Paper I). These magnitudes are based on observations from a synoptic survey (average of 16 epochs) of the central region of the LMC using the CPAPIR camera at the Cerro Tololo Interamerican Observatory 1.5-m telescope between 2006 and 2007. Most of these Cepheid variables were previously studied in the optical V and I bands by the third phase of the Optical Gravitational Lensing Experiment (OGLE-III) survey (Soszynski et al. 2008, J/AcA/58/163; Ulaczyk et al. 2013, J/AcA/63/159). The V and I band mean magnitudes are also compiled in Paper I. The calibration into the 2MASS photometric system, extinction corrections, and the adopted reddening law are discussed in detail in Paper I. (4 data files).

Mixed mobile ion effect on a.c. conductivity of boroarsenate glasses

Indian Academy of Sciences (India)

In this article we report the study of mixed mobile ion effect (MMIE) in boroarsenate glasses. DSC and a.c. electrical conductivity studies have been carried out for MgO–(25−)Li2O–50B2O3–25As2O3 glasses. It is observed that strength of MMIE in a.c. conductivity is less pronounced with increase in temperature and ...

Direct amplitude detuning measurement with ac dipole

Directory of Open Access Journals (Sweden)

S. White

2013-07-01

Full Text Available In circular machines, nonlinear dynamics can impact parameters such as beam lifetime and could result in limitations on the performance reach of the accelerator. Assessing and understanding these effects in experiments is essential to confirm the accuracy of the magnetic model and improve the machine performance. A direct measurement of the machine nonlinearities can be obtained by characterizing the dependency of the tune as a function of the amplitude of oscillations (usually defined as amplitude detuning. The conventional technique is to excite the beam to large amplitudes with a single kick and derive the tune from turn-by-turn data acquired with beam position monitors. Although this provides a very precise tune measurement it has the significant disadvantage of being destructive. An alternative, nondestructive way of exciting large amplitude oscillations is to use an ac dipole. The perturbation Hamiltonian in the presence of an ac dipole excitation shows a distinct behavior compared to the free oscillations which should be correctly taken into account in the interpretation of experimental data. The use of an ac dipole for direct amplitude detuning measurement requires careful data processing allowing one to observe the natural tune of the machine; the feasibility of such a measurement is demonstrated using experimental data from the Large Hadron Collider. An experimental proof of the theoretical derivations based on measurements performed at injection energy is provided as well as an application of this technique at top energy using a large number of excitations on the same beam.

Observation of multi-scale oscillation of laminar lifted flames with low-frequency AC electric fields

KAUST Repository

Ryu, Seol

2010-01-01

The oscillation behavior of laminar lifted flames under the influence of low-frequency AC has been investigated experimentally in coflow jets. Various oscillation modes were existed depending on jet velocity and the voltage and frequency of AC, especially when the AC frequency was typically smaller than 30 Hz. Three different oscillation modes were observed: (1) large-scale oscillation with the oscillation frequency of about 0.1 Hz, which was independent of the applied AC frequency, (2) small-scale oscillation synchronized to the applied AC frequency, and (3) doubly-periodic oscillation with small-scale oscillation embedded in large-scale oscillation. As the AC frequency decreased from 30 Hz, the oscillation modes were in the order of the large-scale oscillation, doubly-periodic oscillation, and small-scale oscillation. The onset of the oscillation for the AC frequency smaller than 30 Hz was in close agreement with the delay time scale for the ionic wind effect to occur, that is, the collision response time. Frequency-doubling behavior for the small-scale oscillation has also been observed. Possible mechanisms for the large-scale oscillation and the frequency-doubling behavior have been discussed, although the detailed understanding of the underlying mechanisms will be a future study. © 2009 The Combustion Institute.

File list: His.PSC.10.H3K56ac.AllCell [Chip-atlas[Archive

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Full Text Available His.PSC.10.H3K56ac.AllCell mm9 Histone H3K56ac Pluripotent stem cell SRX873352,SRX8...73346,SRX873350,SRX873348 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.10.H3K56ac.AllCell.bed ...

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Full Text Available His.PSC.50.H4K16ac.AllCell mm9 Histone H4K16ac Pluripotent stem cell SRX212325,SRX2...98193,SRX212326,SRX298194 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.50.H4K16ac.AllCell.bed ...

File list: His.PSC.20.H4K16ac.AllCell [Chip-atlas[Archive

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Full Text Available His.PSC.20.H4K16ac.AllCell mm9 Histone H4K16ac Pluripotent stem cell SRX298193,SRX2...12325,SRX212326,SRX298194 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.20.H4K16ac.AllCell.bed ...

Historical Analysis of the Inorganic Chemistry Curriculum Using ACS Examinations as Artifacts

Science.gov (United States)

Srinivasan, Shalini; Reisner, Barbara A.; Smith, Sheila R.; Stewart, Joanne L.; Johnson, Adam R.; Lin, Shirley; Marek, Keith A.; Nataro, Chip; Murphy, Kristen L.; Raker, Jeffrey R.

2018-01-01

ACS Examinations provide a lens through which to examine historical changes in topic coverage via analyses of course-specific examinations. This study is an extension of work completed previously by the ACS Exams Research Staff and collaborators in general chemistry, organic chemistry, and physical chemistry to explore content changes in the…

Technical feasibility and reliability of passive safety systems of AC600

International Nuclear Information System (INIS)

Niu, W.; Zeng, X.

1996-01-01

The first step conceptual design of the 600 MWe advanced PWR (AC-600) has been finished by the Nuclear Power Institute of China. Experiments on the passive system of AC-600 are being carried out, and are expected to be completed next year. The main research emphases of AC-600 conceptual design include the advanced core, the passive safety system and simplification. The design objective of AC-600 is that the safety, reliability, maintainability, operation cost and construction period are all improved upon compared to those of PWR plant. One of important means to achieve the objective is using a passive system, which has the following functions whenever its operation is required: providing the reactor core with enough coolant when others fail to make up the lost coolant; reactor residual heat removal; cooling and reducing pressure in the containment and preventing radioactive substances from being released into the environment after occurrence of accident (e.g. LOCA). The system should meet the single failure criterion, and keep operating when a single active component or passive component breaks down during the first 72 hour period after occurrence of accident, or in the long period following the 72 hour period. The passive safety system of AC-600 is composed of the primary safety injection system, the secondary emergency core residual heat removal system and the containment cooling system. The design of the system follows some relevant rules and criteria used by current PWR plant. The system has the ability to bear single failure, two complete separate subsystems are considered, each designed for 100% working capacity. Normal operation is separate from safety operation and avoids cross coupling and interference between systems, improves the reliability of components, and makes it easy to maintain, inspect and test the system. The paper discusses the technical feasibility and reliability of the passive safety system of AC-600, and some issues and test plans are also

Normatização de medidas acústicas da voz normal

Directory of Open Access Journals (Sweden)

Araújo Simone Adad

2002-01-01

Full Text Available Introdução: A análise acústica da voz com o avanço da tecnologia digital surge como um exame complementar promissor para aumentar a precisão diagnóstica em laringologia. Objetivo: Normatização das medidas acústicas de freqüência fundamental, perturbação e ruído na voz normal de brasileiros dos sexos masculino e feminino. Forma de estudo: Clínico prospectivo. Material e Método: Pesquisa no período de março a agosto de 1997, no Ambulatório de Otorrinolaringologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, com 80 voluntários da cidade de Ribeirão Preto e região, sendo 40 do sexo masculino e 40 do feminino, selecionados por meio de triagem, foram realizadas gravações digitais dos fonemas /a/, /e/ e /i/, originando uma amostra de 240 sinais acústicos submetidos ao Programa de Análise Acústica da Voz, desenvolvido na Escola de Engenharia de São Carlos da Universidade de São Paulo com obtenção das medidas acústicas. Resultados: Foram obtidos valores médios em relação a sexo e fonemas das medidas de: Freqüência fundamental, Jitter (Directional Perturbation Factor, Perturbation Variation Index, Jitter Ratio, Jitter Factor, Period Perturbation Quotient, Shimmer (Directional Perturbation Factor, Amplitude Variation Index, Amplitude Perturbation Quotient, Spectral Noise Level, Harmonic-to-noise ratio, Harmonic-to-noise ratio cepstrum, Normalized Noise Energy e Breathiness ratio. Conclusão: A normatização das medidas acústicas é necessária para conhecer melhor a voz normal. Os valores obtidos são compatíveis em sua grande maioria com à literatura existente.

Technical feasibility and reliability of passive safety systems of AC600

Energy Technology Data Exchange (ETDEWEB)

Niu, W; Zeng, X [Nuclear Power Inst. of China, Chendu (China)

1996-12-01

The first step conceptual design of the 600 MWe advanced PWR (AC-600) has been finished. Experiments on the passive system of AC-600 are being carried out, and are expected to be completed next year. The main research emphases of AC-600 conceptual design include the advanced core, the passive safety system and simplification. The design objective of AC-600 is that the safety, reliability, maintainability, operation cost and construction period are all improved upon compared to those of PWR plant. One of important means to achieve the objective is using a passive system, which has the following functions whenever its operation is required: providing the reactor core with enough coolant when others fail to make up the lost coolant; reactor residual heat removal; cooling and reducing pressure in the containment and preventing radioactive substances from being released into the environment after occurrence of accident (e.g. LOCA). The system should meet the single failure criterion, and keep operating when a single active component or passive component breaks down during the first 72 hour period after occurrence of accident, or in the long period following the 72 hour period. The passive safety system of AC-600 is composed of the primary safety injection system, the secondary emergency core residual heat removal system and the containment cooling system. The design of the system follows some relevant rules and criteria used by current PWR plant. The system has the ability to bear single failure, two complete separate subsystems are considered, each designed for 100% working capacity. Normal operation is separate from safety operation and avoids cross coupling and interference between systems, improves the reliability of components, and makes it easy to maintain, inspect and test the system. The paper discusses the technical feasibility and reliability of the passive safety system of AC-600, and some issues and test plans are also involved. (author). 3 figs, 1 tab.

The Ethylene Biosynthesis Gene CitACS4 Regulates Monoecy/Andromonoecy in Watermelon (Citrullus lanatus).

Science.gov (United States)

Manzano, Susana; Aguado, Encarnación; Martínez, Cecilia; Megías, Zoraida; García, Alicia; Jamilena, Manuel

2016-01-01

Monoecious and andromonoecious cultivars of watermelon are characterised by the production of male and female flower or male and hermaphrodite flowers, respectively. The segregation analysis in the offspring of crosses between monoecious and andromonoecious lines has demonstrated that this trait is controlled by a single gene pair, being the monoecious allele M semi-dominant to the andromonoecious allele A. The two studied F1 hybrids (MA) had a predominantly monoecious phenotype since both produced not only female flowers, but also bisexual flowers with incomplete stamens, and hermaphrodite flowers with pollen. Given that in other cucurbit species andromonoecy is conferred by mutations in the ethylene biosynthesis genes CmACS7, CsACS2 and CpACS27A we have cloned and characterised CitACS4, the watermelon gene showing the highest similarity with the formers. CitACS4 encoded for a type ACS type III enzyme that is predominantly expressed in pistillate flowers of watermelon. In the andromonoecious line we have detected a missense mutation in a very conserved residue of CitACS4 (C364W) that cosegregates with the andromonoecious phenotype in two independent F2 populations, concomitantly with a reduction in ethylene production in the floral buds that will develop as hermaphrodite flowers. The gene does not however co-segregates with other sex expression traits regulated by ethylene in this species, including pistillate flowering transition and the number of pistillate flowers per plant. These data indicate that CitAC4 is likely to be involved in the biosynthesis of the ethylene required for stamen arrest during the development of female flowers. The C364W mutation would reduce the production of ethylene in pistillate floral buds, promoting the conversion of female into hermaphrodite flowers, and therefore of monoecy into andromonoecy.

AC quantum voltmeter for the industry; AC-Quantenvoltmeter fuer die Industrie

Energy Technology Data Exchange (ETDEWEB)

Behr, Ralf [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe 2.63 ' ' Josephson-Effekt, Spannung' ' ; Smandek, Bernhard [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe Q.33 ' ' Technologietransfer' '

2016-09-15

In a first part difficulties and challenges of the novel operation principle, the ''differential scanning system'' are discussed and explained, how with highest metrological precision the proof of principle succeeded. By common research with other national metrology institutes the concept was consolidated and improved. In a second part it was exemplarically illuminated, how by an efficient dovetailing of European and national promotion programs with different application neighbourhood consolidated knowledge of basic metrological research could be transferred to economy and especially small and medium companies. With an AC quantum voltmeter up to 10 V and 1 kHz already a unique commercial device is available. How the development foreseeable goes on illuminates the final part of the article.

Aperture measurements with AC dipole

CERN Document Server

Fuster Martinez, Nuria; Dilly, Joschua Werner; Nevay, Laurence James; Bruce, Roderik; Tomas Garcia, Rogelio; Redaelli, Stefano; Persson, Tobias Hakan Bjorn; CERN. Geneva. ATS Department

2018-01-01

During the MDs performed on the 15th of September and 29th of November 2017, we measured the LHC global aperture at injection with a new AC dipole method as well as using the Transverse Damper (ADT) blow-up method used during the 2017 LHC commissioning for benchmarking. In this note, the MD procedure is presented as well as the analysis of the comparison between the two methods. The possible benefits of the new method are discussed.

A Multi-Functional Fully Distributed Control Framework for AC Microgrids

DEFF Research Database (Denmark)

Shafiee, Qobad; Nasirian, Vahidreza; Quintero, Juan Carlos Vasquez

2018-01-01

This paper proposes a fully distributed control methodology for secondary control of AC microgrids. The control framework includes three modules: voltage regulator, reactive power regulator, and active power/frequency regulator. The voltage regulator module maintains the average voltage of the mi......This paper proposes a fully distributed control methodology for secondary control of AC microgrids. The control framework includes three modules: voltage regulator, reactive power regulator, and active power/frequency regulator. The voltage regulator module maintains the average voltage...... of the microgrid distribution line at the rated value. The reactive power regulator compares the local normalized reactive power of an inverter with its neighbors’ powers on a communication graph and, accordingly, fine-tunes Q-V droop coefficients to mitigate any reactive power mismatch. Collectively, these two....../reactive power sharing. An AC microgrid is prototyped to experimentally validate the proposed control methodology against the load change, plug-and-play operation, and communication constraints such as delay, packet loss, and limited bandwidth....

Soliton motion in a parametrically ac-driven damped Toda lattice

International Nuclear Information System (INIS)

Rasmussen, K.O.; Malomed, B.A.; Bishop, A.R.; Groenbech-Jensen, N.

1998-01-01

We demonstrate that a staggered parametric ac driving term can support stable progressive motion of a soliton in a Toda lattice with friction, while an unstaggered driving force cannot. A physical context of the model is that of a chain of anharmonically coupled particles adsorbed on a solid surface of a finite size. The ac driving force is generated by a standing acoustic wave excited on the surface. Simulations demonstrate that the state left behind the moving soliton, with the particles shifted from their equilibrium positions, gradually relaxes back to the equilibrium state that existed before the passage of the soliton. The perturbation theory predicts that the ac-driven soliton exists if the amplitude of the drive exceeds a certain threshold. The analytical prediction for the threshold is in reasonable agreement with that found numerically. Collisions between two counterpropagating solitons is also simulated, demonstrating that the collisions are, effectively, fully elastic. copyright 1998 The American Physical Society

Neural network based PWM AC chopper fed induction motor drive

Directory of Open Access Journals (Sweden)

Venkatesan Jamuna

2009-01-01

Full Text Available In this paper, a new Simulink model for a neural network controlled PWM AC chopper fed single phase induction motor is proposed. Closed loop speed control is achieved using a neural network controller. To maintain a constant fluid flow with a variation in pressure head, drives like fan and pump are operated with closed loop speed control. The need to improve the quality and reliability of the drive circuit has increased because of the growing demand for improving the performance of motor drives. With the increased availability of MOSFET's and IGBT's, PWM converters can be used efficiently in low and medium power applications. From the simulation studies, it is seen that the PWM AC chopper has a better harmonic spectrum and lesser copper loss than the Phase controlled AC chopper. It is observed that the drive system with the proposed model produces better dynamic performance, reduced overshoot and fast transient response. .

The effect of ac-driven force on superlubricity in a two-dimensional Frenkel-Kontorova model

International Nuclear Information System (INIS)

Lin Maimai

2010-01-01

By using the molecular dynamic simulation method with a fourth-order Runge-Kutta algorithm, a two-dimensional dc- and ac-driven Frenkel-Kontorova model with a square symmetry substrate potential for a square lattice layer has been investigated in this paper. For this system, the effects of many different parameters on the static friction force have been studied in detail. It was found that not only the amplitude and frequency of the ac-driven force, but also the direction of dc- and ac-driven forces and the misfit angle between two layers have a strong influence on the static friction force. This indicated that the phenomenon of superlubricity appears easily with larger ac amplitude and smaller ac frequency for some special direction of the external driving force and misfit angle.

Inhibition of acrolein-stimulated MUC5AC production by fucoidan in human bronchial epithelial cells.

Science.gov (United States)

Pokharel, Yuba Raj; Yoon, Se Young; Kim, Sang Kyum; Li, Jian-Dong; Kang, Keon Wook

2008-10-01

Fucoidan, a marine sulfated polysaccharide has both antithrombotic and anti-inflammatory effects. We determined the effect of fucoidan on MUC5AC expression in a human bronchial epithelial cell line, NCI-H292. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that fucoidan inhibited MUC5AC expression and protein secretion in cells stimulated with acrolein, a toxic aldehyde present in tobacco smoke. The activation of both nuclear factor-kappa B (NF-kappa B) and activator protein 1 (AP-1) are key steps in the transcriptional activation of MUC5AC. We found that the acrolein-mediated transactivation of MUC5AC was selectively dependent on AP-1 activation and was suppressed by fucoidan. Fucoidan-induced AP-1 inhibition and MUC5AC repression might be associated with fucoidan's protective effects against respiratory diseases.

Composite Based EHV AC Overhead Transmission Lines

DEFF Research Database (Denmark)

Sørensen, Thomas Kjærsgaard

and analysed with regard to the possibilities, limitations and risks widespread application of composite materials on EHV AC overhead transmission lines may present. To form the basis for evaluation of the useability of composite materials, dierent overhead line projects aimed at reducing the environmental...

Reliability of the emergency ac-power system at nuclear power plants

International Nuclear Information System (INIS)

Battle, R.E.; Campbell, D.J.; Baranowsky, P.W.

1982-01-01

The reliability of the emergency ac-power systems typical of several nuclear power plants was estimated, the costs of several possible improvements was estimated. Fault trees were constructed based on a detailed design review of the emergency ac-power systems of 18 nuclear plants. The failure probabilities used in the fault trees were calculated from extensive historical data collected from Licensee Event Reports (LERs) and from operating experience information obtained from nuclear plant licensees. It was found that there are not one or two improvements that can be made at all plants to significantly increase the industry-average emergency ac-power-system reliability, but the improvements are varied and plant-specific. Estimates of the improvements in reliability and the associated cost are estimated using plant-specific designs and failure probabilities

Electroporation of cells using EM induction of ac fields by a magnetic stimulator

International Nuclear Information System (INIS)

Chen, C; Robinson, M P; Evans, J A; Smye, S W; O'Toole, P

2010-01-01

This paper describes a method of effectively electroporating mammalian cell membranes with pulsed alternating-current (ac) electric fields at field strengths of 30-160 kV m -1 . Although many in vivo electroporation protocols entail applying square wave or monotonically decreasing pulses via needles or electrode plates, relatively few have explored the use of pulsed ac fields. Following our previous study, which established the effectiveness of ac fields for electroporating cell membranes, a primary/secondary coil system was constructed to produce sufficiently strong electric fields by electromagnetic induction. The primary coil was formed from the applicator of an established transcranial magnetic stimulation (TMS) system, while the secondary coil was a purpose-built device of a design which could eventually be implanted into tissue. The effects of field strength, pulse interval and cumulative exposure time were investigated using microscopy and flow cytometry. Results from experiments on concentrated cell suspensions showed an optimized electroporation efficiency of around 50%, demonstrating that electroporation can be practicably achieved by inducing such pulsed ac fields. This finding confirms the possibility of a wide range of in vivo applications based on magnetically coupled ac electroporation.

Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

Science.gov (United States)

Gallegos-Lopez, Gabriel [Torrance, CA; Nagashima, James M [Cerritos, CA; Perisic, Milun [Torrance, CA; Hiti, Silva [Redondo Beach, CA

2012-02-14

A system is provided for controlling two AC machines. The system comprises a DC input voltage source that provides a DC input voltage, a voltage boost command control module (VBCCM), a five-phase PWM inverter module coupled to the two AC machines, and a boost converter coupled to the inverter module and the DC input voltage source. The boost converter is designed to supply a new DC input voltage to the inverter module having a value that is greater than or equal to a value of the DC input voltage. The VBCCM generates a boost command signal (BCS) based on modulation indexes from the two AC machines. The BCS controls the boost converter such that the boost converter generates the new DC input voltage in response to the BCS. When the two AC machines require additional voltage that exceeds the DC input voltage required to meet a combined target mechanical power required by the two AC machines, the BCS controls the boost converter to drive the new DC input voltage generated by the boost converter to a value greater than the DC input voltage.

Electroporation of cells using EM induction of ac fields by a magnetic stimulator

Energy Technology Data Exchange (ETDEWEB)

Chen, C; Robinson, M P [Department of Electronics, University of York, Heslington, York YO10 5DD (United Kingdom); Evans, J A [Academic Unit of Medical Physics, University of Leeds, Leeds LS2 9JT (United Kingdom); Smye, S W [Department of Medical Physics and Engineering, Leeds Teaching Hospitals, St. James' s University Hospital, Leeds LS9 7TF (United Kingdom); O' Toole, P [Department of Biology, University of York, Heslington, York YO10 5DD (United Kingdom)

2010-02-21

This paper describes a method of effectively electroporating mammalian cell membranes with pulsed alternating-current (ac) electric fields at field strengths of 30-160 kV m{sup -1}. Although many in vivo electroporation protocols entail applying square wave or monotonically decreasing pulses via needles or electrode plates, relatively few have explored the use of pulsed ac fields. Following our previous study, which established the effectiveness of ac fields for electroporating cell membranes, a primary/secondary coil system was constructed to produce sufficiently strong electric fields by electromagnetic induction. The primary coil was formed from the applicator of an established transcranial magnetic stimulation (TMS) system, while the secondary coil was a purpose-built device of a design which could eventually be implanted into tissue. The effects of field strength, pulse interval and cumulative exposure time were investigated using microscopy and flow cytometry. Results from experiments on concentrated cell suspensions showed an optimized electroporation efficiency of around 50%, demonstrating that electroporation can be practicably achieved by inducing such pulsed ac fields. This finding confirms the possibility of a wide range of in vivo applications based on magnetically coupled ac electroporation.

Effective Peroxidase-Like Activity of Co-Aminoclay [CoAC] and Its Application for Glucose Detection

Directory of Open Access Journals (Sweden)

Han Pill Song

2018-02-01

Full Text Available In this study, we describe a novel peroxidase-like activity of Co-aminoclay [CoAC] present at pH ~5.0 and its application to fluorescent biosensor for the determination of H2O2 and glucose. It is synthesized with aminoclays (ACs entrapping cationic metals such as Fe, Cu, Al, Co., Ce, Ni, Mn, and Zn to find enzyme mimicking ACs by sol–gel ambient conditions. Through the screening of catalytic activities by the typical colorimetric reaction employing 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic aciddiammonium salt (ABTS as a substrate with or without H2O2, Fe, Cu, and CoACs are found to exhibit peroxidase-like activity, as well as oxidase-like activity was observed from Ce and MnACs. Among them, CoAC shows exceptionally high peroxidase-like activity, presumably due to its ability to induce electron transfer between substrates and H2O2. CoAC is then used to catalyze the oxidation of Amplex® UltraRed (AUR into a fluorescent end product, which enables a sensitive fluorescent detection of H2O2. Moreover, a highly sensitive and selective glucose biosensing strategy is developed, based on enzyme cascade reaction between glucose oxidase (GOx and CoAC. Using this strategy, a highly linear fluorescence enhancement is verified when the concentration of glucose is increased in a wide range from 10 μM to 1 mM with a lower detection limit of 5 μM. The practical diagnostic capability of the assay system is also verified by its use to detect glucose in human blood serum. Based on these results, it is anticipated that CoAC can serve as potent peroxidase mimetics for the detection of clinically important target molecules.

Isolated PDM and PWM DC-AC SICAMs[Pulse Density Modulated; Pulse Width Modulated

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.

2004-03-15

In this report a class of isolated PDM and PWM DC-AC SICAMs is described, which introduce the audio reference only in the output stage. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitor. Isolation from the AC mains is achieved using a high frequency (HF) transformer, receiving the HF voltage pulses from the input 'inverter' stage and transferring them to the output 'rectifier+inverter' stage, which can use either PDM or PWM. The latter stage is then interfaced to the load using an output low-pass filter. Each of the dedicated stages is discussed in detail. Measurements on the master/slave PWM DC-AC SICAM prototype are presented to help benchmarking the performance of this class of SICAMs and identify the advantages and drawbacks. (au)

Phase-locking of driven vortex lattices with transverse ac force and periodic pinning

International Nuclear Information System (INIS)

Reichhardt, Charles; Kolton, Alejandro B.; Dominguez, Daniel; Gronbech-Jensen, Niels

2001-01-01

For a vortex lattice moving in a periodic array we show analytically and numerically that a new type of phase locking occurs in the presence of a longitudinal dc driving force and a transverse ac driving force. This phase locking is distinct from the Shapiro step phase locking found with longitudinal ac drives. We show that an increase in critical current and a fundamental phase-locked step width scale with the square of the driving ac amplitude. Our results should carry over to other systems such as vortex motion in Josephson-junction arrays

Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis